Assuming you are referring to Companions, i.e. non combat pets:
It depends on which Faction/Race you are playing, for example there is a vendor in Elwynn Forest situated on the west side of the road leading to Northshire that sells different kinds of cats. There tends to be one of these vendors related to each of the individual races, but are available to that race's entire faction.
Otherwise many are often available on either the Alliance/Horde Auction House, or the Neutral Auction House in Booty Bay, as well as the rarer kinds of companion that are attainable only via the Blizzard Store, in game seasonal events, or drops from certain dungeon and raid encounters (like the parrot that drops in the final ship-dock room of the Deadmines).
My apologies if you were actually referring to the Hunter specific, combat pets, in which case I would point out that they are not bought, but tamed using the Hunter's Tame Pet ability.
There is no Small pet , Non - combat pet , companion that is based off a Peacock in WoW.
Talk to a stable master, buy one or more slots for your pets, and click the empty slot to put your pet in it.
You buy it.
You can buy bets from different vendors or on the Auction House. Also hunters can capture their own pets at level 10.
You cant
No, you can not buy my world of warcraft account, i have put too much time and money into it.
No.
You can purchase an item called "Nurtured Penguin Egg" that allows you to summon "Pengu".
i think that with the undead pet yes
A Retail World of Warcraft Server costs money. In the USA it is $15.00 a month +Tax and you have to buy the games and get an account. Once you get a subscription and buy the games you then can Connect to a Retail World of Warcraft Server.
Yes.
Don't buy gold. It ruin's the World of Warcraft economy, most of the time the money comes from exploits in the game, and it is Illegal.