Most people love them. Some people couldn't care less. There is probably a collective of cold-hearted individuals out there who hate them. Unfortunately for them, more and more players will be collecting vanity pets due to two changes: one, the removal of pet carriers as items that take up bag space and their replacement as summoning spells that characters can learn upon acquisition of a new pet, and two, the associated achievements:
Can I Keep Him? (Obtain 1 Vanity Pet)
Plenty of Pets (Collect 15 unique vanity pets)
Plethora of Pets (Collect 25 unique vanity pets)
Shop Smart. Shop Pet... Smart (Collect 50 unique vanity pets)
The final one has a reward attached: A Stinking Pet Carrier. I. Wants. One!
Since I'm obviously not alone, WoW Insider included this excellent post on a few fairly easy-to-obtain pets we may have missed. Worg puppies are adorable, so I'll have to finish that quest for sure! The chicken quest will probably be a little more difficult for an RP-er, but I may just play temporary insanity or have Frijona liquor up first.
A few extra tips:
1. The sprite darter that can be obtained in Feralas. Wowwiki has a guide to the quest chain. (Sorry Hordies, this one is Alliance only.)
2. Faction-specific pets can be found in the neutral auction houses.
3. If you completed a quest with a pet reward and deleted your pet, you can get it back by going to a stable-master. Sometimes, however, this doesn't work and you have to open a ticket with a GM.
4. Engineers can make the mechanical squirrel which is bind on equip, so it can be auctioned off. It's a fairly low-level schematic (Sprynklez knows it already).
5. Winter Veil is coming up, with companion pets as presents and rewards.
[Image: A tiny spore bat from Wowwiki. The tiny spore bat is my favorite vanity pet in the game. What's yours?]