Mycoloth

Devour is a one-time bargain: sacrifice creatures on arrival, get twice that many counters back stapled to a body. Most creatures with the keyword spend that windfall immediately, on a fat one-shot threat. This one converts it into an engine. The upkeep trigger turns every counter into a fresh Saproling each turn, and since the tokens are creatures, they feed the next devour, the next combat, the next sacrifice outlet. The math compounds in a way that few green creatures of its era did: a turn-five drop that ate two creatures starts the following turn making four bodies, then four more, then four more, with each new arrival able to fuel another devourer or a sacrifice payoff. The design's elegance is that the counters do double duty: they are the stats that make the 4/4 a clock, and they are the rate at which it floods the board. That coupling is also its risk. Counters vanish when the creature dies, so any answer that hits Mycoloth doesn't just kill a threat, it shuts off the token spigot and erases the investment poured into the devour. A static token-maker keeps ticking regardless of how it survives; this one stakes everything on living through a single upkeep. It is the rare snowball that punishes patience on both sides: leave it standing and the board drowns in green; answer it a beat too late and the counters have already paid for themselves.