Tyrael's Hilt



Tyrael's Hilt summons an in-game companion angel, Mini Tyrael. He responds to emotes such as, and was one of the first companions to fly.

Source
Participants of the 2008 Blizzard Worldwide Invitational in France were given a code that unlocked this pet in-game.

The item can be acquired from the following NPCs by redeeming the WWI promotion codes:
 * in Undercity's Trade Quarter
 * in Stormwind City's Trade District

Tyrael's Hilt can still be obtained in-game, provided you have or somehow acquire an unused redemption code.

Pet Journal
 'I am Justice itself!' 

Trivia

 * His name and appearance comes from Archangel Tyrael, a character from Blizzard's Diablo series.