Introduction

Originally a pet for Sorcerers and Wizards, familiars have become great utility and combat options easily on par with Animal Companions. This article also includes a comprehensive list of available familiar options, including those from feats like Improved Familiar.

Table of Contents

Disclaimer

RPGBOT uses the color coding scheme which has become common among Pathfinder build handbooks, which tend to be more consistent than 3.5 handbooks. Because so little of 3.5 is available on the SRD, I will attempt to tag items with a superscript indicating their book of origin. For help identifying sourcebook abbreviations, see my Sourcebook Abbreviations Guide.

  • Red: Bad, useless options, or options which are extremely situational. Nearly never useful.
  • Orange: OK options, or useful options that only apply in rare circumstances. Useful sometimes.
  • Green: Good options. Useful often.
  • Blue: Fantastic options, often essential to the function of your character. Useful very frequently.

It’s important to note that I generally omit campaign-setting specific content. I am of the opinion that those options are intended to be limited to campaigns run in those settings, and as such they don’t really apply to a generic campaign. Those options also tend to be wildly unbalanced and rarely receive errata. I also omit the use of “Flaws” since they allow a massive increase in power with essentially no cost to the character.

Familiars in the Party

Because Familiars determine their abilities based on their master’s hit points, BAB, and skills, familiars can fill many roles in the party as well as or sometimes better than their master.

Basic Familiars

Common among Sorcerers and Wizards who make no effort to capitalize on their Familiars, a basic Familiar is still an excellent tool. They can serve as a delivery mechanism for touch spells, and because of their small size and good Dexterity they are often excellent at Hide and Move Silently, allowing them to move into position to attack before the party kicks in the door. They can also act as couriers for Exploding Runes and Sepia Snake Sigil, or for delivering messages non-magically to nearby recipients.

Apprentice Familiars

If your GM allows it, your Familiar may be able to use magic items, especially if you have Use Magic Device. This can make your familiar extremely useful if you hand them wands of Lesser Vigor, or scrolls/wands offensive spells which don’t allow saving throws, like Grease. Remember that Spell Trigger items like wands and Command Word items both require that the user be able to speak.

Skilled Familiars

Especially useful if they have opposable digits, familiars can serve as Scouts nearly as well a Rogue. They lack Trapfinding, and can’t get the ability from their master, so be wary of traps.

The exact mechanics of other skills are somewhat suspect. A wizard’s familiar gets the same modifier to Knowledge skills, but I don’t think any reasonable DM would allow a familiar to make a Knowledge check. Similarly, if your familiar can speak you might be able to use your familiar as the party’s Face if your Dm allows it. You might also let your familiar make spot/listen/search checks by itself, but the ability to provide the Alertness feat seems to be intended to reflect your familiar aiding you.

Combat Familiars

The biggest reason to pick up Improved Familiar (or any of the other special familiar feats) is because you want to turn your familiar into a fighting animal. There is a fantastically long list of wonderful options (see “Expanded Familiar Options”, below), many of which can be very capable combatants. Because familiars use their master’s BAB and calculate their HP based on their masters, combat familiars generally work best for combat classes like Duskblade and Hexblade.

Feats

  • Bonded FamiliarPHB2: Allows you or your familiar to save each other’s life. Hopefully you never need it.
  • Celestial FamiliarBoED: The lantern archon and musteval guardinal are absolutely fantastic options as both support and light damage output, which makes them fantastic for conventional casters, but not useful for combat casters.
  • Combat FamiliarPHB2: Good for casters who like to deliver touch spells through their familiar, but not helpful for combat familiars.
  • Dragon FamiliarDr: It’s important to note that Dragon Familiar uses a different familiar ability progression. This delays the lowest-level familiar abilities a bit, but because dragons can already speak you skip the speech abilities, and pick up Spell Resistance and Scry on Familiar a few levels late. Despite these issues, Dragons are a great choice of familiar; they can fly, they can speak, they’re intelligent, they have opposable digits, and they have breath weapons. Because their breath weapon damage will be terrible as wyrmlings, you want a dragon with a save or suck breath weapon. Familiars are treated as using their master’s character level for effects related to hit dice, including ability progression like the DCs of breath weapons. This makes breath weapons with status effects (especially save or suck effects) extremely potent, as they can keep pace with their master’s highest DC spells and can be used every 1d4+1 rounds. Because only metallic dragons get status effect breath weapons, chromatic dragons are worthless.
  • Obtain FamiliarCAr: Opens up familiars for arcane caster who don’t usually get them like Duskblades.
  • Stitched Flesh FamiliarLM: Turns your familiar into an undead creature. Very situational, and based on the wording it probably doesn’t work with feats which grant additional familiar options.
  • Lurking FamiliarPHB2: I have never heard of an enemy standing next to a spellcaster and choosing to attack their familiar instead. Why would you? If it ever becomes a problem, send your familiar to hide in a corner or something.
  • Spell-Linked FamiliarPHB2: Imbue Familiar with Spell Ability is strictly better, and allows your familiar to use your full caster level. You could combine the two, but that seems like a lot of investment for a minor aspect of your build.

Spells

  • Augment FamiliarCW: The bonuses are fantastic, but because the spell’s duration is Concentration it prohibits you from doing anything interesting while you run the spell. As cool as your familiar may be, you are still the character, and a spellcaster should have much cooler options than whatever their familiar can do.
  • Enhance FamiliarCAr: Absolutely essential for combat familiars. Hours/level duration so you can run it all day.
  • Familiar Pocket:CAr: Amusing, but almost never matters. Go buy a bag of holding and put your familiar in it.
  • Familiar RefugeCM: Interesting as a swift action. You might be able to come up with some very handy uses for this, but don’t expect it to be a go-to option.
  • Fortify FamiliarCAr: Great for combat familiars, but not quite as essential as Enhance Familiar. Hours/level duration so you can run it all day on top of Enhance Familiar, but remember that the temporary hit points only last for an hour.
  • Imbue Familiar with Spell AbilityCAr: Turn your Familiar into a tiny Wizard! Give it buff spells to enhance your allies while you’re doing something more important, or give it attack spells for extra damage output. Low-level spells with no save like the lesser elemental orb spells are good options because they do decent damage, and with a Familiar’s size and typically high dexterity they may be better at touch attacks than you are. At high levels this is a fantastic way to improve your action economy.

Items

  • Collar of HealingMIC: Heal your familiar for 50 once per. It doesn’t list an action to activate, which means that it takes a Standard Action, and wasting a Standard Action on healing in combat is generally not a good idea. 50 hit points looks tempting, even out of combat, but for the 5000 gp price you can buy 6 wands of Lesser Vigor, and still have a pile of gold left over.
  • Familiar’s BeltCM: Unless you really like delivering touch attacks with your familiar, this is worthless.
  • Rod of Spell ChannelingCM: An interesting option, but rarely worth the cost.

Familiar Options

Basic Familiar Options

Basic familiar options are available to Sorcerers, Wizards, and any character who takes the Acquire FamiliarCAr feat.

Familiar Alignment Reqs. Source Special
Albatross Any Sw Master gains a +1 bonus on Spot checks
Arctic Fox Any FrB Master gains +3 bonus on Move Silently checks
Bat Any PHB Master gains a +3 bonus on Listen checks
Cat Any PHB Master gains a +3 bonus on Move Silently checks
Dire Rat Any Huge or larger DMG Master gains a +2 bonus on Fortitude saves
Eel Any Sw Master gains a +3 bonus on Escape Artist checks
Ferret Any Tiny or smaller DMG Master gains a +2 bonus on Reflex saves
Fish Owl (Owl) Any Sw Master gains a +3 bonus on Spot checks in shadows
Gyrfalcon (Hawk) Any FrB Master gains +3 bonus on Spot checks
Hawk Any PHB Master gains a +3 bonus on Spot checks in bright light
Hedgehog Any Tiny or smaller DMG Master gains a +1 natural armor bonus
Horned Lizard Any Sa
Huitzil Any Dr Master gains a +3 bonus on Sleight of Hand checks when the master and familiar are within 1 mile of each other.
Lemming (Rat) Any FrB Master gains +2 bonus on Listen and Spot checks
Leopard Any Huge or larger DMG Master gains a +2 bonus on Move Silently checks
Lizard Any PHB Master gains a +3 bonus on Climb checks
Monitor Lizard Any Huge or larger DMG Master gains +3 hit points
Mouse Any Tiny or smaller DMG Master gains a +2 bonus on Move Silently checks
Octopus Any Sw Master gains a +3 bonus on grapple checks
Owl Any PHB Master gains a +3 bonus on Spot checks in shadows
Owl (Medium) Any Huge or larger DMG Master gains a +2 bonus on Move Silently checks
Parrot (Raven) Any Sw Raven Master gains a +3 bonus on Appraise checks. A parrot familiar can speak a language of its master’s choice as a supernatural ability.
Penguin Any FrB Master gains +2 bonus on Fortitude saves
Puffin (Raven) Any FrB Master gains +2 bonus on Swim and Survival checks
Rat Any PHB Master gains a +2 bonus on Fortitude saves
Raven Any PHB Master gains a +3 bonus on Appraise checks. A raven familiar can speak one language of its master’s choice as a supernatural ability.
Raven (Small) Any Huge or larger DMG Speaks one language
Screech Owl Any Tiny or smaller DMG Master gains a +2 bonus on Move Silently checks
Sea Snake Any Sw Master gains a +3 bonus on Bluff checks
Snake Any PHB Tiny viper. Master gains a +3 bonus on Bluff checks
Snowy Owl (Owl) Any FrB Has low-light vision; master gains +3 bonus on Move Silently checks
Thrush Any Tiny or smaller DMG Speaks one language
Toad Any PHB Master gains +3 hit points
Viper Snake, Medium Any Huge or larger DMG
Weasel Any PHB Master gains a +2 bonus on Reflex saves
Wolverine Any Huge or larger DMG Master gains a +2 bonus on Reflex saves
Albatross
The albatross is unusually large for a Familiar, which makes it a very big target for enemies. It flies, but no better than a Hawk, Owl, or Raven. The only potential benefit is that it might be able to carry a Tiny rider.
Arctic Fox
The arctic fox has nothing interesting except Scent, which plenty of better options also get.
Bat
With flight, low-light vision, and blindsense the Bat is a portable sensor. The +3 bonus to listen is helpful, but few arcane spellcasters get Spot or Listen as class skills, so the bonus will fall off after low levels. Once your familiar gains the ability to speak to you at level 5, it can spot nearby invisible enemies and point them out for you and your allies to attack.
Cat
Hilariously effective at killing 1st-level Commoners and other weak humanoids, the cat is a good generic familiar. Cats get racial bonuses to Hide and Move Silently, making them excellent Scouts if their master doesn’t invest in stealth. Unfortunately the +3 bonus to Move Silently will be wasted on most spellcasters, but Arcane Tricksters and other Rogue/Caster hybrids may enjoy having a cat. Cats also have Scent, which allows them to detect nearby creatures, though you won’t be able to locate them.
Dire Rat
Only accessible to Huge or larger masters, the Dire Rat doesn’t do anything that the Rat can’t do better. Filth Fever is amusing, but because diseases take several days to take effect it will never come up in combat.
Eel
Basically an underwater weasel. Unless you’re in an underwater campaign, the eel will never be a good option.
Ferret
Only available to Tiny or smaller masters. No stats are provided for ferrets. As a DM, I would likely use a Diminutive weasel.
Hawk
With a +16 to spot, the Hawk will easily outstrip its master’s Spot checks until mid levels, even with the +3 bonus to Spot from having a Hawk familiar. Hawks fly, which is great for delivering touch attacks, but other flying options are better at stealth (owls) or can detect invisible creatures (bat).
Hedgehog
Only available to Tiny or smaller masters. No stats are provided for hedgehogs. I don’t even know what you could convert into a hedgehog. A weaker version of the horned lizard’s spikes attached to a diminutive rat might be a good start.
Horned Lizard
The horned lizard can spray blood from its eyes, and deals a puny amount of damage if attacked with natural weapons. The horned lizard also gets a burrow speed, but a spellcaster can get a lot more from other options.
Huitzil
The Huitzil flies, and appears to have opposable digits. It gets a racial bonus to Sleight of Hand and Search checks, which make it a good fit for Rogue/Caster hybrids. The Distract ability is also amusing, but certainly dangerous to use.
Leopard
Only available to Huge or larger masters, the Leopard is a bigger and scarier version of the Cat. With Improved Grab and Rake, the Leopard is a perfectly viable Striker, especially if the master has decent BAB and hit points.
Lizard
The Lizard is all about climbing, and climbing is dumb when flight is so easy.
Monitor Lizard
Only available to Huge or larger masters, the monitor lizard is a bite attack with a swim speed. There are better combat options, and swimming isn’t very useful.
Mouse
No stats are provided for mice, so I’m not sure what to do with this. As a DM, I would just make a Diminutive version of the Rat.
Octopus
An octopus is a scary predator to its prey, but when most things are medium (and therefore bigger than the octopus), its Improved Grab ability is worthless.
Owl
Basically a stealthy version of the Hawk, and the Owl’s Spot bonus applies in dim light conditions, like those common to dungeons.
Penguin
The penguin has a good swim speed, and can hold its breath for a very long time, but for aquatic campaigns you want something that can live in the water, and for land campaigns you want something that has a decent move speed.
Rat
Less lethal but more versatile than the cat, the rat has both climb and swim speeds, allowing it to function in many situations. It has Scent, which allows it to detect the presence of nearby creatures, and it has respectable stealth skills without relying on its master. The provided +2 bonus to Fortitude is nice for full casters who typically have poor Fortitude saves.
Raven
The raven (and other birds which are basically pallet-swaps of the raven) can fly and speak a language. While this may be enough for some people, your familiar rarely has anything useful to say to anyone but you, and you can talk to your familiar at level 5. If your DM will allow your familiar to use wands, the raven is likely the only basic familiar which can do so since they can speak.
Screech Owl
Only available to Tiny or smaller masters. No stats are provided for screech owls. As a DM, I would likely use a Diminutive owl.
Sea Snake
Nearly identical to the snake, but with a higher poison DC, and a better swim speed than its land speed.
Snake
The snake’s big appeal is its poison. At 1d6 constitution damage, viper poison can be dangerous at any level. However, with a DC of only 10 you will have a lot of trouble getting enemies to fail their saving throws. You may be able to harvest poison from your familiar if someone in the party can use it.
Thrush
Only available to Tiny or smaller masters, no stats are provided for the Thrush. As a DM, I would probably make a diminutive version of the Raven.
Toad
Dismally slow, no useful abilities, and 3 hit points is garbage. It can’t even swim. Somehow the toad gets a +21 to Hide, but the ability to sit still and not be noticed is not enough to redeem the toad.
Viper Snake, Medium
Basically the same as the Snake, but bigger and with a very slightly higher poison DC.
Weasel
A climb speed and scent are the weasel’s biggest advantages, but the Rat has those plus a swim speed, and Reflex saves aren’t as important as Fortitude saves. The Attach special ability is amusing, but in practice it won’t do anything useful.
Wolverine
Only available to Huge or larger masters. The Wolverine is basically a bigger, scarier badger with Rage. The Leopard will be a better combat option for what few casters can select between the two, but there’s something to be said for having a pet barbarian.

Expanded Familiar Options

Additional familiar options are available with feats like Improved FamiliarVarious and Celestial FamiliarBoED.

Familiar Alignment Level Reqs. Feat Source Special
Air Elemental, Small Any 5th Air Subtype Improved DMG
Air Elemental, Small N 5th Planar PH
Anarchic Animal Any C 3rd Planar PH Apply the template to any animal from the standard familiar list. Unlike other improved familiars, these creatures grant their masters the standard benefits for having an animal familiar of that type.
Axiomatic Animal Any L 3rd Planar PH Apply the template to any animal from the standard familiar list. Unlike other improved familiars, these creatures grant their masters the standard benefits for having an animal familiar of that type.
Badger N 3rd Improved CS
Black Dragon N, NE, CE 8th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Blade Guardian Any 11th Improved CW Costs gold to create body, and gets reduce familiar abilities. See Complete Warrior.
Blink Dog LG 5th +5 BAB Improved CW
Blue Dragon LN, LE, NE 10th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Brass Dragon NG, CG, CN 9th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Bronze Dragon LG, LN, N 11th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Celestial Animal Any G 3rd Celestial BoeD Apply the celestial template to any animal from the standard familiar list. Unlike other celestial familiars, a celestial animal grants its master the standard benefit for having an animal familiar of that type.
Celestial Animal Any Good 3rd Good Subtype Improved DMG Apply the celestial template to any animal from the standard familiar list. Unlike other celestial familiars, a celestial animal grants its master the standard benefit for having an animal familiar of that type.
Celestial Animal Any G 3rd Planar PH Apply the template to any animal from the standard familiar list. Unlike other improved familiars, these creatures grant their masters the standard benefits for having an animal familiar of that type.
Copper Dragon CG, N, CN 10th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Coure Eladrin CG 7th Celestial BoeD
Earth Elemental, Small Any 5th Earth Subtype Improved DMG
Earth Elemental, Small N 5th Planar PH
Fiendish Animal Any Evil 3rd Evil Subtype Improved DMG Apply the fiendish template to any animal from the standard familiar list. Unlike other celestial familiars, a fiendish animal grants its master the standard benefit for having an animal familiar of that type.
Fiendish Animal Any E 3rd Planar PH Apply the template to any animal from the standard familiar list. Unlike other improved familiars, these creatures grant their masters the standard benefits for having an animal familiar of that type.
Fire Elemental, Small Any 5th Fire Subtype Improved DMG
Fire Elemental, Small N 5th Planar PH
Formian LN 7th Improved DMG
Gauntlet Guardian Any 9th Improved CW Costs gold to create body, and gets reduce familiar abilities. See Complete Warrior.
Gold Dragon LG, NG, LN 14th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Green Dragon N, LE, NE 9th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Hell Hound LE 5th +5 BAB Improved CW
Hippogriff N 7th +7 BAB Improved CW
Homunculus Any Undead Improved DMG The master must first create the homunculus, substituting ichor or another part of the master’s body for blood if necessary.
Howler CE 7th +7 BAB Improved CW
Imp LE 7th Improved DMG
Imp LE 7th Planar PH Standard only. If you are using the Fiend Folio, you may use a filth imp instead.
Krenshar N 3rd +3 BAB Improved CW
Lantern Archon LG 7th Celestial BoeD
Lantern Archon LG 7th Planar PH
Mephit (Any) N 7th Improved CS
Mephit (Any) Any Matching subtype Improved DMG
Mephit (Any) N 7th Planar PH
Monstrous Centipede, Small N 2nd Improved CS
Monstrous Scorpion, Small N 3rd Improved CS
Monstrous Spider, Small N 4th Improved CS
Musteval Guardinal NG 7th Celestial BoeD
Pseudodragon N 7th Improved DMG
Quasit CE 7th Improved DMG
Quasit CE 7th Planar PH
Red Dragon CN, CE, NE 12th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Shocker Lizard N 5th Improved DMG
Shocker Lizard Any 5th Elecricity Subtype Improved DMG
Silver Dragon LG, NG, N 12th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Spark Guardian Any 7th Improved CW Costs gold to create body, and gets reduce familiar abilities. See Complete Warrior.
Stirge N 5th Improved DMG
Viper, Medium N 3rd Improved CS
Vargouille NE 6th Improved CS Vargouilles summoned as familiars do not possess the Kiss supernatural ability.
Water Elemental, Small Any 5th Water Subtype Improved DMG
Water Elemental, Small N 5th Planar PH
White Dragon N, CN, CE 7th Dragon Dr Uses special Familiar ability progression; see Draconomicon.
Winter Wolf NE 7th +7 BAB Improved CW
Worg N 3rd +3 BAB Improved CW
Air Elemental, Small
The Air Elemental can fly very quickly and with perfect maneuverability, but that’s it’s only interesting ability. The Vortex ability only works on creatures at least on size smaller than the elemental, so unless you’re fighting a lot of cats it’s completely useless.
Anarchic Animal
The aligned creature templates is a decent template, but none of the base familiar options are viable in combat, the templates are largely wasted.
Axiomatic Animal
The aligned creature templates is a decent template, but none of the base familiar options are viable in combat, the templates are largely wasted.
The badger is like a tiny furry barbarian. It gets three attacks, but even with rage its damage is poor. It’s a decent low level combat familiar, especially with a bit of buffing, but it won’t scale well as you advance in level.
Black Dragon
All it can do is damage, and even then it can’t do a lot of it.
Blade Guardian
The Blade Guardian is a higher level and more expensive equivalent to the Gauntlet Guardian. Despite the increased cost, it is not notably more durable, and it actually does less damage. The Blink Dog is a fantastic flanking partner due to its ability to easily get into flanking position. It can also quickly move to interpose itself between enemies and weak allies. It lacks strong offensive options, but if you just need a reliable way to flank it’s absolutely fantastic.
Blue Dragon
All it can do is damage, and even then it can’t do a lot of it.
Brass Dragon
Roughly equivalent to the Silver dragon. Sleep and Paralysis are largely the same, though it is easier to be awoken than to be cured of paralysis.
Bronze Dragon
The Bronze dragon’s breath weapon causes enemies to flee, but somehow isn’t a fear effect. Causing enemies to flee removes them from a fight just as well as paralyzing them, but while they’re running it can be hard to kill them.
The aligned creature templates are decent templates, but none of the base familiar options are viable in combat, so the templates are largely wasted.
Copper Dragon
Copper dragons have a Slow breath weapon, but Slow can’t really match the effectiveness of the Silver dragon’s paralyzing breath, but it’s a decent debuff and far fewer things are immune to it.
Coure Eladrin
The coure eladrin matches the Lantern Archon’s magic circle against evil, and has many of the same spell-like abilities as the musteval guardinal, but can only cast magic missile 3/day before running out of offensive options.
Earth Elemental
At small size the earth elemental is basically a pushy child with Earth Glide. It will do nothing useful in or out of combat.
Fiendish Animal
The aligned creature templates are decent templates, but none of the base familiar options are viable in combat, so the templates are largely wasted.
Fire Elemental, Small
The fire elemental’s only redeeming quality is Burn, and at small size it’s not going to be likely to hit anything. Go cast Summon Monster instead.
Formian
The DMG doesn’t specify which type of formian you get, but I would assume a worker. If that is the case, the formian worker is worthless. Formian workers are only useful in groups, and even then they’re hardly interesting.
Gauntlet Guardian
The gauntlet guardian is reasonably durable with DR 5/- and fast healing 1, but its attack are pitiful, leaving it to fall into the classic tank dilemma: if no one can hurt you, and you can’t hurt them, why should they try to hurt you?
Gold Dragon
If you’re looking for a breath weapon, the silver dragon is strictly better. The gold dragon’s redeeming quality is that it is medium size, and has an absurd fly speed of 200. While its poor maneuverability makes it difficult to ride into the close confines of combat, 200 feet is still pretty incredible, and at medium size a gold dragon wyrmling can serve as a mount for a small master.
Green Dragon
The only interesting thing that the green dragon has to offer is its acid breath, which deals a pitiful 2d6 damage. It may be able to use magic items, especially if you have Use Magic Device, but so can every other dragon familiar.
Hell Hound
Very cool, but all it does it damage, and two levels later you can get a Winter Wolf, which does more damage, has Trip, and is a size category larger.
Hippogriff
At large size, the hippogriff can serve as a mount for medium creatures, and with an impressive 100 foot fly speed it’s faster than using Fly. The hippogriff’s attacks aren’t spectacular, but it has darkvision, low-light vision, and scent, so it can function in a lot of situations and detect the presence of nearby enemies. This is a great option for spellcasters who want to remain at a distance, but may not have easy access to flight, as well as for combat spellcasters like duskblades who want something that can fight and help them get around. Remember that casting a spell while riding a mount requires a Concentration check, so be sure to boost your Concentration bonus.
Homunculus
Homunculi are specifically designed to be messengers and scouts, and that is just what they’re good for. They have a sleep poison which you might be able to use, but the DC is low so it won’t remain useful past low levels. If you’ve spent a feat on Improved Familiar you can find much better options.
Howler
At large size, the Howler can serve as a mount for medium creatures. Its bite is formidable, and the Howler’s Quills ability can really help to bring down tough enemies if they fail a few reflex saves. The Howl ability won’t help much in combat, but if you can trap enemies somewhere you can send your howler off to howl a bunch and drive them insane until they fall comatose.
Imp
The demon equivalent of the quasit, the imp is the superior of the two. They have a dexterity damage poison which you may be able to harvest, but they’re not much use in combat. However, they get to use Detect Good, Detect Magic, and Invisibility (self only) at will. Invisibility makes them an excellent Scout, and and with DR and fast healing they’re durable enough to survive being thrown into a few traps. Imp can use alternate form to turn into a few things, but they’re mostly only useful as disguises. Imps have opposable digits (they have human-like hands), and can probably use magic items if you have Use Magic Device. The thing that set sets them above quasits is the ability to cast Commune once per week and ask their deity 6 questions. Commune has an experience cost, but spell-like abilities ignore material components and experience costs, you can use your Imp familiar to query the DM at no cost.
Krenshar
The krenshar’s attacks are mediocre, and its Scare ability will stop being effective very quickly.
Lantern Archon
All archons have an Aura of Menace ability, and despite the low DC the lantern archon can inflict some nasty penalties to enemies. It also has an ongoing Circle of Protection Against Evil, providing you and your party with nice bonuses to saves and AC against evil creatures, and protecting you from evil summoned creatures. As an archon in can teleport itself and 50 pounds of gear, making it a fantastic courier and messenger, and it has a permanent Tongues effect, allowing it to serve as a flying translator. Despite their names, Lantern Archons don’t appear to provide light, but they can shoot lasers to deal 1d6 damage as a touch attack, making them a reliable (if not very intimidating) source of damage in combat.
Mephit
Mephits come in many forms, each with slightly different abilities. Even mephit has a breath weapon and some spell-like abilities, and fast healing which works under specific circumstances. Mephits can fly and have Darkvision, which can make them useful scouts, but they’re not stealthy at all. Unfortunately the DCs of their abilities are terrible and won’t scale as you level, so your mephit will quickly stop being useful.
  • Air: Breath weapon only does damage (and only 1d8), and their best spell-like ability is Gust of Wind.
  • Dust: The breath weapon debuff is decent, but the DC is terrible. Wind Wall is very situational.
  • Earth: Useless breath weapon, and Soften Earth and Stone is useless. Earth mephits can increase their size to medium once per hour, but I’m not certain why they would do so.
  • Fire: All it can do is damage, and even then not very much.
  • Ice: The breath weapon applies a nice debuff, but dust mephits have better spell-like abilities.
  • Magma: The breath weapon applies a nice debuff, but the special abilities are garbage.
  • Ooze: The breath weapon applies a nice debuff, and the spell-like abilities aren’t totally worthless.
  • Salt: The breath weapon applies a nice debuff, and glitterdust is a great way to handle invisible enemies. The ability to suck moisture out of the air is interesting, but the damage is pitiful.
  • Steam: The breath weapon applies a nice debuff, but the spell-like abilities are useless.
  • Water: The same spell-like abilities as the ooze mephit, but with a worse breath weapon.
Monstrous Centipede
Worse than the mosntrous spider with identical poison and no web.
Monstrous Scorpion
Less versatile than the Monstrous Spider, but its poison deals constitution damage. Monstrous scorpions get constrict and improved grab, but at small size they can’t grapple very well.
Monstrous Spider, Small
At small size, the monstrous spider’s web only affects medium creatures, and its poison DC is terrible for a tiny bit of Strength damage. If you want to entangle enemies, go get a net. If you want to poison things, get a snake.
Musteval Guardinal
The Musteval is a personal favorite of mine. They’re a cat-sized humanoid rodent angel of some sort, and they can do a whole lot of great things. They have a whole bunch of skills, including respectable Hide and Move Silently bonuses, they have a burrow speed, they have celestial energy resistances and immunities, they have permanent Tongues effect (pet translator!), and their Focused Movement ability is basically Fly-By attack on the ground. They have humanoid hands, so they can hold hold and use magic items if you have UMD. On top of all of that, they get spell-like abilities! They get invisibility once per day for scouting, and they get several others including Magic Missile at caster level 3. That means that your Musteval can be awesome outside of combat, then spend fights sitting in a corners slinging 2d4+2 damage every round effectively forever.
Pseudodragon
With blindsense and telepathy, pseudodragons a great way to detect and handle invisible creatures. They are good flyers, and have an impressive +20 to hide. Pseudodragons also have a sleep poison, and putting enemies to sleep essentially kills them. The DC is low, and pseudodragons aren’t useful in combat, so see if you can harvest the poison and hand it to someone in the party.
Quasit
The demon equivalent of the imp, quasits are tiny demons mostly dedicated to annoying people. They have a dexterity damage poison which you may be able to harvest, but they’re not much use in combat. However, they get to use Detect Good, Detect Magic, and Invisibility (self only) at will. Invisibility makes them an excellent Scout, and and with DR and fast healing they’re durable enough to survive being thrown into a few traps. Quasits can use alternate form to turn into a few things, but they’re mostly only useful as disguises. Quasits have opposable digits (they have human-like hands), and can probably use magic items if you have Use Magic Device.
Red Dragon
Red dragons are the most powerful of chromatic dragons, but they’re not useful as familiars. They have a breath weapon which deals 2d10 fire damage, but by the time that they are available as familiars there are many better options.
Shocker Lizard
Shocker Lizards are only scary in groups.
Silver Dragon
Silver Dragons are among the most powerful true dragons. They have impressive mental stats, and they have a paralyzing breath weapon. Their breath weapon paralyzes enemies for 1d6+1 rounds, easily long enough for someone to walk over and make a coup de grace. Dragon familiars can likely also use magic items, so hand your familiar a wand of something cool to use between breath weapons. Silver Dragons also get Alternate Form, and can turn themselves into a medium animal or a humanoid.
Spark Guardian
The spark guardian costs 2000gp to make (plus the 500 for the lab), It can fly, but not particularly well, It can shoot sparks as a touch attack, but 2d6 damage isn’t great. It has DR 5/-, fast healing 1, and it’s a construct, so it’s extremely durable. You have the option of spending additional gold to craft a Spark Guardian with more hit dice, but guardian familiars still use their master’s BAB and half of their master’s HP if they are higher than the familiars, so there is no reason to do so. Also remember that guardian familiars are mindless, which limits the familiar’s capabilities considerably. If you want to replace your familiar with a mindless turret, you can do worse than the Spark Guardian. If you want useful tactical and utility options, look elsewhere.
Stirge
The stirge attacks as a melee touch attack, so it can charge into melee and hit some of the toughest enemies without issue. It drains blood fast enough that it only needs to remain attached for 2 rounds on average, at which point you’ve dealt 4 points of constitution damage. The stirge’s only problem is that once it’s done feeding it’s useless until it finishes digesting. The monster manual entry doesn’t mention how long it takes the stirge to digest, but it’s probably a few hours at least, if not a full day. Beyond Blood Drain, the stirge is a mediocre flyer with Darkvision and Low-Light Vision, which can make it a decent scout in dark caves and dungeons, but a Bat will be more effective.
Viper, Medium
This is mediocre as an option even without spending a feat on it.
Vargouille
Darkvision and flight are fine, but the Varguille’s big draw is Shriek. Vargouille familiars don’t get the Kiss ability, which means that they’re essentially Shriek on wings. Unfortunately, the DC is only 12 so it’s going to be very hard to find enemies who are likely to fail the check. Your best bet is to have your Varguille Shriek at your party every morning (WAKE UP) to make them immune for 24 hours, then have it Shriek again at the beginning of every fight and hope that you enemies roll a 1.
Water Elemental, Small
The water elemental is only useful for its Vortex ability, which is only usable underwater and is dependent on the elemental’s size.
White Dragon
White Dragons are easily the weakest of true dragons, and they’re not better as familiars. With 6 intelligence and 6 charisma they’re nothing special to talk to, and their breath weapon does 1d6 cold damage. Basically the only thing that they’re good for is flying, and possibly for using magic items.
Winter Wolf
The winter wolf is large, making it a potential mount for medium riders. It has a breath weapon, though the damage is poor, and its bit attacks deal cold damage. The most important part of the winter wolf is that is has Trip. At Large size and with 18 Strength, it can be an excellent tripper, and a great combat familiar for melee characters.
Worg
The worg is basically an intelligent wolf. At medium size it can serve as a mount for small creatures (at least according to The Hobbit), and with Trip the worg can be a an excellent combat familiar for other melee characters. As you advance in level, you will want to trade in your Worg for a Winter Wolf.