Thanks kind people.

Can buy/sell them here. Learn them, and recage on any server to sell/ transfer em

Pets have essentially turned into WoW's equivalent to Pokemon, in the sense that you can catch wild pets, level your current pets, and battle other "trainers" for achievements, titles and what not.
Most pets can be caged and traded, with a few exceptions like BlizzCon and Collector's Edition pets.

These guides might help, they are extremely in-depth and detailed on the subject:

http://www.wowhead.com/guide=1179/pet-battles-and-you-a-trainers-manual
http://www.wowhead.com/guide=1212/battle-pets-and-where-to-find-them

This post was edited by Arkhen on Sep 26 2017 11:44am

i literally have a bank full of boe pets

have not logged on since the release of the recent expansion lol.

i cant believe i spent like 1 million gold on token just to stop playing..oh well.