Pets that look like other ingame pets or player forms...
An Imp (or other warlock demon)
A Shadowpriest's Shadowfiend or a more "pet" version of the Haunter Memento "Eye of Naxx" look.
A mini-druid cat and bear (there are moonkins and trees)
Mini-water elemental for a Mage

A hyperactive Chiuhua that just keeps going Yip, Yip, Yip, Yip...
and when combat starts, gets scared and runs away....
comes back when your out of combat like nothings happened.

With 5.0 on the distant horizon, Im planning to pace myself on these pets... 5.0 supposedly brings all the pets to being account wide, if that is true. Im having my alts farm and store tickets for those pets. While my main focuses on the mounts first. Pacing myself this way by having 3 alts each ear...

If I had all the collector edition pets... Starcraft Dream Team: Grunty, Zergling, Mini Thor Diablo Dream Team: Mini Diablo, Mini Tyrael, Murkablo If I was being silly.... Orphan Death Squad: Argent Squire, Curious Wolvar Pup, Curious Oracle Hatchling Whats for Dinner: Elwynn Lamb, Plump Turkey, Lit...

I wonder if the Squires and Heralds and Xmas Helpers would be exempt... seems unfair to have children and men fight pets. Also what happens to the pets that normally interact... will Rocket Bots one shot each other, will the Creepy Crate eat all contenders, will Stinky scare away any and all black c...