Creature — Horror 1/1, 1B (2)
Common
When Abyssal Gatekeeper dies, each player sacrifices a creature.
"There are two ways for me to pass this gate. One involves you remaining conscious."
—Gerrard of the Weatherlight
Illus. Mark Tedin

10/4/2004: The "sacrifice a creature" effect is not targeted. It can affect creatures with protection from black.
4/1/2008: 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.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander