Magmasaur

A countdown clock built into a creature, and a clean expression of one of red's oldest tensions: the bigger the payoff, the longer you wait for it, and the whole time you are bleeding the asset that powers it. The body arrives at full size, but it functions as a timer that ticks on your upkeep. Each turn poses the same choice: shave a counter to keep it on the table for one more attack step, or let it detonate for everything it has left. That decision structure carries the whole design. Detonation only happens on your upkeep, and only when you decline to remove a counter, so the maximum payoff is locked behind a full turn of patience and shrinks by one with every upkeep you let it survive. The damage clause is doing careful work in what it spares: by hitting each creature without flying and each player, it acts as a one-sided sweeper for any deck operating under the radar of an evasive threat, while pressuring the opponent's life total in the same swing. The cadence keeps it honest: the trigger is locked to your upkeep, so you cannot hold the threat indefinitely and you cannot fire it at instant speed in response to a profitable block. It is a board wipe you have to schedule a turn in advance, and the scheduling is the game.