Primates: WoW Battle Pets
Select a pet:

World Event: Darkmoon Faire (first week of each month)
Vendor: Lhara
Zone: Darkmoon Island
Cost: 90 (unlimited supply)
Drop: Darkmoon Game Prize
Zone: Darkmoon Island
Approximate Drop Rate: 1 in 1,250

TIP: You can search for a specific pet using any word found in the pet's name or item. You can also search using obvious keywords like "robot," which will return all robot-like pets.