Lil' Deathwing

Lil' Deathwing is the in-game companion acquired by purchasing World of Warcraft: Cataclysm Collector's Edition. He is a smaller version of Deathwing.

Source
Similar to past companions rewarded through purchasing the Collector's Editions, this item will be mailed to all characters on the account.

Accompanying letter
The letter delivered with Lil'Deathwing is from The WoW Dev Team: