Abyssal Gatekeeper
Duel Decks Anthology: Divine vs. Demonic — common
Creature — Horror
Abyssal Gatekeeper rulings:
2008-04-01: The player whose turn it is chooses a creature to sacrifice, then each other player in turn order chooses a creature to sacrifice, then all chosen creatures are sacrificed at the same time.
2004-10-04: The "sacrifice a creature" effect is not targeted. It can affect creatures with protection from black, for example.