Reduces the cooldown on Raise Dead by 60 sec, and the Ghoul summoned by your Raise Dead spell is considered a pet under your control. Unlike normal Death Knight Ghouls, your pet does not have a limited duration.
Patch 3.1.0 (2009-04-14): Now also reduces the cooldown on Raise Dead by 60 sec.
Patch 4.0.1 (2010-10-12):Unholy, primary abilites: Master of Ghouls (Passive) - Reduces the cooldown on Raise Dead by 60 sec, and the Ghoul summoned by your Raise Dead spell is considered a pet under your control. Unlike normal Death Knight Ghouls, your pet does not have a limited duration. Translation: This ability is gained as soon as you spec an Unholy talent?