Pets have always been a great money maker in world of warcraft, in fact they've been a huge part of my gold making ever since I've picked up engineering. I've since then expanded to all types of pets, from snowmans to oozes, and even whelps.
You read right, whelps. These little buggers have obscenely low drop rates from specific mobs around Azeroth, which can be taken for as a con or a pro. It's a con because, of course the drop rate is low that you'll spend a fair bit of time farming the mobs that drop them, but it's worth it because a single whelp can net your anywhere from 5-10,000g. You can become instantly rich overnight!
There are four total whelps, and in this post, I will cover all of them, where to farm them and such, do keep in mind that Blizzard made these pets a zone drop, for example The Tiny Crimson Whelp is a zone drop from Wetlands.
You can also kill/farm any other mob in Winterspring( please correct me here ) to get a chance at this pet, I liked this spot because you also have a chance at the Icy Chill formula.
This is the dark version of the four whelps. There are multiple zone where you can farm this little pet, either one will do fine, but Badlands seems like it has a little higher % to drop the pet.
Please do keep in mind that all of these whelps are and have now become Zone wide drops ( according to a couple people in the JMTC IRC ). This guide simply shows you the best spots in my opinion to farm these whelps, there might be better spots within these Zones, but like I said, I found these to be fairly good farming spots. Best of luck to any of you going for these whelps!