Vengeful Dead
The drain payoff at the center of early Zombie aggro, and the piece that turned a tribe of disposable bodies into reach. The shells it lived in had no trouble stacking the graveyard with cheap, recursive undead; what they lacked was a way to convert all that dying into damage that did not need to get past blockers. This answers that exactly. The trigger keys off death rather than attack or sacrifice, which means the deck's own chump blocks, removal-bait, and fetch chains all feed the clock. Mass-death effects flip from setback to payoff, and an opponent's sweeper becomes a self-inflicted wound: every Zombie it kills drains them. The 3/2 body is deliberately soft, because the card is not built to win combat, it is built to make losing combat irrelevant by taxing every trade. It even drains for its own death, so the moment it gets blocked, burned, or swept it still pays out. That is the structural ancestor of the aristocrats logic that Blood Artist and Zulaport Cutthroat later generalized across all creatures; here the effect is locked to a single tribe, which is both the constraint that prices it and the reason it only ever mattered inside a dedicated Zombie deck. Outside one it is a fragile attacker whose death trigger fires for one life, which is to say almost nothing. Inside one, it is why a board of small undead becomes a guaranteed clock no matter how the combat math falls.

