Crimson Whelpling Farming Location (Classic - WoTLK)
The Tiny Crimson Whelpling is the lowest level out of combat pet whelping that you're able to farm. Luckily, or unluckily, depending on what faction you're playing, the only place to farm this whelp is in The Wetlands. Specifically in the eastern portion of the zone just outside the area where you have to do Test of Skulls for the Onyxia quest chain. This out of combat pet has about a .5% chance of dropping from any of the red colored whelps in this area.
If you're playing on a PvP server, I would consider this farming location more of an Alliance only one. Unless you're level 60 at which point you'll easily be able to defend yourself as a Horde player. Low level Alliance players (between 25 - 30) have the added benefit of being able to farm this whelp while also earning EXP.
Additionally, if you're a Skinner you'll make even more gold while farming here since you'll be able to skin the whelps! You'll find Light Leather as well as Medium Leather from Skinning these. Miners will find Copper Veins and Tin Veins in the area whereas Herbalists will find a bunch of different Herbs. The best selling ones will be Kingsblood, Briarthorn and Mageroyal, not only because they are valuable herbs but because they can also contain Swiftthistle.
Another thing that's worth mentioning is the whelps will drop greens and blues which could potentially be a best in slot twink item. I've created two lists of all the BiS twink items mostly for people who are looking to buy and resell them, but they're also useful for things like this. Level 19 BiS Twink Items and Level 29 BiS Twink Items. If you get one of the items on that list, I'd recommend selling it on the AH instead of vendoring it.
Of course your chance of actually finding the Tiny Crimson Whelpling pet is extremely low, however if you do find it - it'll be a large chunk of gold in your pocket... Assuming you don't use the pet yourself! Keep in mind that since this is a vanity item, its price will continue to rise as the amount of gold in the market inflates. If you find this item while your server is still new, it won't be worth as much as once your server stabilizes and people start spending their gold on silly stuff, like pets.
Items of Interest
Grey Items to Vendor