Harpy Youngling
Source: Pet Battle. They only get more beautiful as they age. Humanoid type. I summon Harpie Lady, in attack mode!
The Harpy Youngling is a wild humanoid battle pet found in The Dry Hills region of Kalimdor, captured through standard pet battle.
Guide awaiting review
Travel to The Dry Hills
Head to The Dry Hills and begin your search at 25.07, 26.59, working through the area toward 26.78, 27.99 and 27.44, 28.05 where Harpy Younglings are known to spawn.
Walk the Spawn Points
Move through the area on foot rather than flying, looping between 27.17, 29.67, 26.37, 29.35, and 26.8, 31.01 while watching your minimap for pet battle icons.
Clear Critters Near Harpies
Kill any critters you find near the harpy mobs around 24.61, 32.85 and 27.46, 32.09, as players have reported that clearing these critters causes one to two Harpy Younglings to respawn per pass.
Battle and Capture
Once a Harpy Youngling appears, engage it in a pet battle and use a Rare-quality capture method to attempt catching it — at max level 25 and Rare quality, the Harpy Youngling has 1400 health with 260 power and 260 speed.
Tips
Harpy Younglings are humanoid type pets, so bring a beast-type battle pet for a damage advantage during the capture battle.