Sprite Darter Egg



Sprite Darter Egg is used to summon Sprite Darter Hatchling, a faerie dragon companion.

Source
This item is a rare drop from mobs in Feralas.

This companion was previously a quest reward from Becoming a Parent. Since patch 4.0.3a, the quest chain has been removed from the game.

When Patch 3.1.0 was released, Horde members could obtain this pet as well.

Pet Journal
"These adorable critters love snuggling with their owners after a long day of brutal, bloody battle."