Whisperwood Elemental — Duskmourn: House of Horror Commander #204

At the beginning of your end step, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Sacrifice this creature: Until end of turn, face-up nontoken creatures you control gain "When this creature dies, manifest the top card of your library."