Bioplasm

Whenever this creature attacks, exile the top card of your library. If it's a creature card, this creature gets +X/+Y until end of turn, where X is the exiled creature card's power and Y is its toughness.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6odwsu9tkvpb1hxx1v7stu.