Giant Adephage

The terror here is not the 7/7 trampling body; it is the compounding math behind it. Each copy that connects spawns exactly one more, so a single unblocked hit gives you two attackers, and if both get through next turn you have four, then eight: the board doubles every combat step the opponent fails to fully stop. Trample does not force the trigger, but it turns most chump-blocking into a delaying tactic. Assign lethal to a small blocker, spill the rest onto the player, and the token arrives anyway. The clean way to deny a copy is to eat the whole attack without any damage reaching the player: block with something (or a wall of somethings) whose combined toughness soaks every point of trample, or prevent or remove the damage outright. Anything short of that, and the arithmetic marches on. The fragility is that the engine produces nothing on the turn it lands: it sits summoning-sick, and a single instant-speed removal spell or a fog erases the trigger, so the whole apparatus rests on one swing surviving to combat. That tension (an exponential payoff gated behind a slow, vulnerable body that must live to a combat step) is the entire design. Self-replicating creatures whose threat scales geometrically rather than additively are a rare breed, and the appeal is less the first hit than the arithmetic of the second, where a board you could have raced becomes a board you cannot.