Autochthon Wurm

Fifteen is a number the game almost never asks you to reach, and that absurd cost is the entire point of the design. Convoke is what reconciles a 9/14 trampler with a price tag nobody pays in mana: every creature on the board becomes a fraction of the cost, so a wide green-white board that has stalled out can tap down and slam this in a single turn. The whole design inverts the usual relationship between creature count and casting cost. Most fatties want you to ramp into them; this one wants you to have already won the board-presence war, then cash that lead in for a body big enough to end things. Trample is the closing punctuation, carrying overflow past a chump blocker straight to the player so a wall of small attackers converts into lethal damage all at once. The 14 toughness is the quietly relevant number, sitting above nearly every burn spell and most combat math, so an entire turn's worth of taps will not simply trade down to a damage-based answer. It still folds to a single targeted kill spell or exile effect, of course; the protection here is against the red deck and the chump block, not the clean removal spell that ignores the body's size entirely.