These are...
Bats.

Featured only in a few zones, these undervalued creatures would make a good mount. They look great as companion-sized creatures, but full-sized, perhaps their older model and generally frightening grin turn off a lot of players who would otherwise use them.
Snakes.

Though their current cobra model is fearsome, there are thousands of species of snakes in the world. At least one other model exists in the game, and many of those are not only critters but full-sized mobs with plenty of health such as Marsh Serpent in Uldum. More models could be added, of course, but this would be a good start.
Tarantulas.

These may count as spiders, but all of the other types of spiders are based on the long and spindly-legged models. There are no other creatures with the typical hairy tarantula type body. If these neat arachnids could get another look, preferably with the "spiky" hair smoothed out, I would be very happy.
Devilsaurs.

Although I personally believe their model is fine, they still have only one body type that comes in a pathetic four skins. Just a simple variation, like a sail on the back a la Spinosaurus, or perhaps a crest or two on the head would really spice up this terrifying troupe of theropods.
Hyenas.

Ah, another otherwise interesting pet family plagued by what I like to call the "spiky hair syndrome." Perhaps samba-izing such creatures is not the best decision, as many people oppose his rockin' hairdo, but some smoothing out would certainly help these cackling scavengers attract a mate, or a potential hunter companion.
Tallstriders.

My personal favorite when it comes to hoping for a new model. Though spending time on these forums has shown me what wonderful creatures the tallstriders are (Hahadori, I'm thinking of you) , I have never met a single person that uses a tallstrider ingame. Most people ingame think they are ugly, and would never use one. This seems like a terrible waste of a hunter pet. My proposal for an alternate model is a proper terrorbird. Something that actually strikes fear into the hearts of its enemies, with a beak that looks like it's designed for slicing through flesh and not plants.
Bears.

These tough and loyal protectors are the preferred pet of most dwarfs. They don't currently have much variety in the few skins that exist, as half of them are diseased skins. A new giant panda "bear" skin for Pandaria certainly would fit the new expansion, perhaps a sloth bear or spirit bear?
Beetles.

There are roughly 400,000 species of beetle in our world: so why is there only one model for these creatures? Although there are many bright and colorful skins available, the "scarab" body is the only type available at the moment. There are quite literally thousands of choices to choose from, so why not add a few new species for a new continent? Perhaps a bug with nasty mandibles like the tiger beetle, or maybe those with massive horns like the Hercules and stag beetles.
That's all the one-modeled pet families, so my work here is done! Post your thoughts: what possible models could help these creatures out? You can help the support with fanart, model edits, or real life images.













