Yawgmoth Demon

A demon that taxes its controller in artifacts: the upkeep clause is the entire design, and it predates the modern vocabulary for what we would now call a "cost" or a "drawback creature." The body is oversized for 1994 black (a 6/6 flier with first strike at six mana was, and largely still is, an extraordinary rate), and the design pays for it by demanding a steady stream of artifact sacrifices or punishing you with two damage and a tap that pins the creature down: a tapped demon can't attack at all, so missing the payment costs you both life and a turn of pressure. The home set makes the bargain legible: the deck that runs this is a deck already overflowing with artifacts, and the sacrifice clause becomes a feature when those artifacts carry enter-the-battlefield or leaves-the-battlefield value worth recurring. Strip the artifact context away and the card eats its pilot alive, which is the point. The Yawgmoth name here predates the character's canonization as the Phyrexian antagonist, and the flavor of a demon you feed metal to or it feeds on you sits at the root of what Phyrexian design would later formalize: compleation, the artifact-as-flesh equivalence, the body that demands tribute. The rate looks generous until you read the upkeep; the upkeep looks punishing until you read the deck it was built for.