Rare pet

A rare pet defines a pet that has a rare or unique skin (appearance). In this case, rare or unique means the skin is only possessed by one or a very few difficult to find or acquire mobs.

Since pet stats have been normalized, every pet of a particular type (i.e. cat, boar, bear, etc.) will have exactly the same movement speed, health, and attack speed. Primarily pets of one type are all the same as far as stats go. Pets learns new ranks of abilities as they go up in level. For more pet details and information on taming pets, see Pet (Hunter).

Though some of these pets are difficult to acquire, some hunters consider having a unique or especially good looking pet to be a big part of their enjoyment of the class, and go out of their way to get the perfect one.

Bats
The only rare bat pets are the two white bats, both rare spawns, in Tirisfal Glades and Razorfen Kraul.

Bears
For the most part, bears have generic skins. However the diseased bears of the Western Plaguelands and the rabid grizzlies of Dragonblight have a decayed look to them.

Birds of Prey
Birds of prey have a large variety of skins to choose from, however there are a few with unique skins and colors.

Boars
There are several unique boar skins, particularly those from Razorfen Kraul.

Carrion Birds
The only rare skinned carrion birds are the two-headed variety found in some Outland zones.

Cats
Another very popular pet, there are several extremely rare and striking skins for cats. The white lions are very rare pets for Alliance players to get, since one can only be spawned by a Horde quest, and the other, while also a quest spawn, must be done at Level 60+ for taming purposes.

Chimaeras
If you want something really rare and unique, tame Nuramoc. He has unique skins, really long respawn timer, respawns in different places, is level 70 and requires Exotic Beasts to tame. You can be pretty sure that you're one of few who have this pet.

Crab
Tame Karkin, he has a silver and a gem on its shell. Spawns on Fireplume Peak in the Molten Front.

Crocolisk
White crocolisks such as the Deviate Crocolisk and Deadmire deserve mention, though normal white crocolisks can now be tamed at high level in the Netherstorm in Outland. There is also the Sewer Beast, an especially difficult-to-find rare spawn, in the canals of Stormwind. It has only a slight change in coloration from other crocolisks.

Dragonhawk
Dragonhawks are rare creatures in and of themselves. There are general mob dragonhawks in Shadowmoon Valley, and a more difficult to acquire skin in The Botanica and Tempest Keep.

Gorillas
There is only one rare gorilla skin, and that is Uhk'loc from Un'Goro Crater.

Hyenas
The only rare hyena skin is from the Scarlet Monastery

Owls
There are a few owls which can only be found in Outland dungeons.

Raptor
There are quite a few distinct raptor skins, though most can be found on typical mobs. Outland raptors have quite a sinister appearance. They are fairly easy to get once you reach the zone they are in, so they haven't been included here.

Ravager
Ravager skins are widely varied, seldom with more than one mob for a particular skin. However, there are as of yet no rare spawns or particularly difficult to find ravagers, so each is about equally "rare".

Scorpid
There are currently no unique or rare scorpid pets available.

Serpent
Serpent mobs are fairly rare. Most only appear in instances, and are elite. There is only one type of "normal" serpent, found in Shadowmoon Valley in Outland.

Spiders
There are a lot of spider skins, but only two rare ones.

Sporebats
There are only three sporebat skins currently in game, and only one of those (Sporewing) is unique.

Tallstriders
There are three rare Tallstriders, all with unique skins and all rare spawns or special named mobs.

Turtles
There aren't any unique turtle skins.

Warp Stalker
The typical warp stalker is white with purple stripes. However, there is a species with a unique coloration available in the Netherstorm.

Wind serpents
The wind serpent's few skins that are common are in reality quite rare, since only a few rare spawns have normal pet stats. When looking for a wind serpent pet, check the Wailing Caverns.

It's also worth noting Arikara here. While not a rare skin (it uses the easily accessible red wind serpent skin), it does have a special effect associated with it that remains after taming—whenever the hunter calls the pet, dismounts, or zones in, Arikara will arrive with the same puff of smoke and rumble that occurred when he was summoned during the quest.

Wolves
Wolves are a popular pet and there are many skins. However, only a few of these skins are unique.