The Pet Emote addon is the greatest thing ever designed for WoW.
Many a time those things have defined a pet's personality beyond doubt. For example, my Goblin's Gezzarak, Onyx has a great sense of humour, since every single damn time I laugh at my brother's character (who I level with), Onyx will join in and grin widely at him. Clearly a sharp chap that one.
My Worgen's Duskfang, Byron, on the other hand, is a pretty grumpy guy. He has never yet emoted anything positive, and tends to spend his time growling at various people and grumbling to himself. It suits his looks, which I think is great!
I have foxes on most of my hunters, but it's definitely my Goblin's white one, Pearl who has the most wicked sense of humour. That damn creature is constantly getting up to no good!
I've had that adoring look emote once too, and it made me keep my Goblin's lovely worm, Agate. I had tamed one just to check out what the pet family is like, since I've always been repulsed by the models. But when the pink one came along, I figured it wasn't as bad as the rest and maybe I could have it in use now and again. As soon as I tamed her, she did the "Curling around her mistress' legs and looking up adoringly" bit. My heart thawed a little. A while later we went into a random dungeon with my brother, and she did the emote again. The tank said "Nice pet you've got there! Very friendly." and I laughed and realised that Agate was more than just a test, she was a keeper. And, she will still throw out that emote more often than any other of my 86 pets.
him. I even SQUEED and lol'ed out loud IRL. Roommate looked at me like I was coo-coo. 
