Phantom Tiger

The Phantom mechanic turned damage prevention into a depletion counter, and this is the cleanest illustration of the bargain. The printed toughness is 0, which means the creature exists only as long as its counters do: each instance of damage is fully prevented, but every prevention shaves a +1/+1 counter off the body, and once both counters are gone, a base toughness of 0 immediately sends it to the graveyard. There is no empty corpse phase; the counters are the creature's only structural support, and removing the last one ends it on the spot. That makes it functionally a creature with two lives rather than two health bars. It blocks twice regardless of the attacker's size (a 1/1 and a 10/10 each cost it exactly one counter), then dies, which inverts the usual relationship between a blocker's toughness and the threats it can stop. The wrinkle is that the same counters set its power, so trading away a prevention shrinks its offense as well; soak one hit and the tiger swings for less the next turn. The design rewards spending each prevention against the biggest swing available and punishes chip damage that drains a counter for nothing. It is a small, precise statement of a niche idea: a creature priced not on how much damage it can survive, but on how many times.