If you are above lvl 60, you can get some nice, exotic pets for a very low price at a vendor.
Then you could choose to sell them in AH, keep them, or whatever.
Among those companions you find the mana wyrmling, a cockroach, the siamese cat, a nice little dragon, and then some.
Go to Netherstorm and to Stormspire. There you’ll find the vendor in the tower. He’s called Dealer Rashaad.
If you’re low level, you should definitely have learned flying and fly to Netherstorm, since you will probably not have the flight path, yet.