Here's another quick tip on how to insure a small but steady income. This is valid for most vendor-bought vanity pets, but especially the ones that are located in harder to reach places. Those in limited supply are even better because they fetch higher premiums but you might find it's a waste of time waiting for them to spawn.
So it's back to the old and trusted method of selling vendor pets on the Auction House. The only pet I trade in is the Ancona Chicken. On my server, this pet can be sold at 800% profit on normal days and even double on good days. It is bought for 1 gold from Thousand Needles (see the Wowhead link for more details). Perhaps due to the fact that the location is a bit out of the way, most people prefer to pay 8 gold (or more) for it on the AH. Which is perfectly fine with me. I go to Thousand Needles perhaps once a week and stock up on chickens. Then I post them 1-2 at a time and usually sell 2-3 a day.
Now bear in mind that my way of doing this won't bring you a lot of gold in the short term but it's all part of diversification. The more diverse your wares are, the higher your chances to make a sale. So I get a steady trickle from this pet. Any time it is lower than 8 gold I don't post. Usually by the next day prices are back to "normal".
You can do this with most other vendor-bought pets. Just search Wowhead and after making a list, look them up on the AH and then stock up on them. Don't flood the AH, instead list 1-2 at a time and replenish as soon as they sell. I would stick to cheaper pets, around the 1 gold vendor price. More expensive ones might be risky when trying to re-sell them. Just watch your server's Auction House for a week or two so you can get a feeling for how these pets are selling.
Patch 1.0.5 commentary
3 years ago