Part of the Haruspex's Garb set:

The set gives these bonuses as more pieces are worn: 2: Restores 4 mana per 5 sec. 3: Increases the duration of Faerie Fire by 5 sec. 5: Increases the critical hit chance of your Starfire spell 3%. Set Details | All Sets

Quest Reward from:

Level	Name	Start	Rewards
60	Paragons of Power: The Haruspex's Tunic  (Raid) Horde and Alliance Zul'Gurub	Maywiki of Zuldazar Stranglethorn Vale	6600 XP