Malefic Armor
From WoWWiki
Tier 6 warlock armor is collectively known as Malefic Armor. One set is currently available:
The wing animation is tied to the head piece, and randomly appears once every few minutes. It appears at different times on each client. The blue version is used for part of the Season 3 Arena set ([Vengeful Gladiator's Felweave Cowl] and [Vengeful Gladiator's Dreadweave Hood]) and a green set.
It does not allow you to fly.
