Tyrranax

Green pump spells overwhelmingly trade toughness down for power up: the bigger swing, the riskier block. This beast runs the lever the other way. For per activation it shaves a point of power and banks a point of toughness, walking the 5/4 toward a wall: 4/5, 3/6, 2/7, as deep as your mana stretches. The body becomes a beater that can choose to bounce off a larger blocker and survive, or shrink under burn and slip beneath a lethal point at instant speed in response to a removal spell. You rarely want both halves on the same turn, and the mana cost is what stops you from having them for free; you commit to attacking big or holding small, and the green payment is how you choose. It is a creature that asks you to read combat backward, sizing for what you need to absorb rather than what you need to deal, which makes it a quieter and stranger green design than the toughness-shedding pump effects of its era. The ability never refreshes power on its own, so the toughness you bank stays banked until end of turn, rewarding the player who knows precisely how much damage is coming.