Text (LO): 6/6, Fear. ; Whenever a creature deals damage to you, destroy it. ; When ~this~ is put into a graveyard from anywhere, shuffle it into its owner's library.
The second ability is different from a "goes to the graveyard from play" ability in that it triggers after it is in the graveyar and not as it leaves play. This means that if it lost the ability while in play, it would still trigger, but if it loses its ability in the graveyard (as with Yixlid Jailer) that it won't trigger. [Lorwyn FAQ 2007/09/25]