How do you get a pet or companion in WOW

Combat Pets: Hunters, Warlocks, Frost Mages, and Unholy Death Knights all have a permanent pet that they can use for fighting, with hunters and warlocks being able to choose which one they want to use. Hunters can tame beast found in the world to use while warlocks just learn the spells that summon their demon minions. Frost mages and Unholy Death Knights do not get to choose what their pet is, there is only one, the Water Elemental (Frost Mage) and the Ghoul (Unholy Death Knight).

Non-Combat Pets: There are many ways to get non-combat pets in World of Warcraft. Most capital cities have a vendor in or near them that will sell a cheap companion, as well as various other vendors out in the world. They also drop off of certain bosses in Dungeons and raids, and there are a few quest lines that will reward you with a pet. If you REALLY REALLY want a pet and are having trouble finding them in game, you can also purchase certain pets in the Blizzard Store online.