Cleaver Skaab

The trick is that the tokens are copies of the sacrificed Zombie, not generic 2/2s: feed it something that carries an enters-the-battlefield trigger, a death trigger, or a static anthem effect, and every activation converts one body into two of whatever engine piece you fed it. That turns the ability from a modest doubler into a chassis for exponential value in the right shell, since the copies are themselves Zombies eligible for the next activation. The costs are the ballast that keep it from spiraling on turn one: three generic mana plus the tap plus a nonself Zombie sacrifice mean each loop demands a real fodder supply and a way to untap or wait a turn. That gating is why it reads as a build-around rather than a standalone threat: the 2/4 body invites no combat plan, and the ability does nothing until you have a Zombie worth doubling. Structurally it sits in the lineage of sacrifice-and-recur engines, but it inverts the usual math. Most such outlets trade a creature for value once; this one hands back two of the same creature, so the graveyard is beside the point and the battlefield does the accumulating. It rewards a decklist where every Zombie earns its slot on a trigger rather than a stat line.