Amphibious Kavu

A green common whose entire payload is a conditional combat bonus aimed at two specific colors. Set it across from blue or black in the red zone and it swells from a plain 2/2 to a 5/5 for the turn; against red or white boards, it has nothing to say. That conditionality is what pays for the rate, an artifact of color-tuned design where stats spike only against an enemy color rather than scaling on a generic curve. The trigger reads cleanly off enemy-color theory: green's structural rivals were the controlling, removal-heavy decks, and this Kavu was a body sized to push through them in combat. Two limits keep the design grounded. First, the bonus fires only on blocking or being blocked, so the upside is a combat-math swing, not a passive buff: it does nothing on an empty board or against a creature that never trades blows. Second, it has no evasion and no reach, so its job is on the ground against creatures it can actually meet, not as an answer to fliers. What dates it is the assumption underneath the trigger, that a green deck's opposition would reliably wear blue, black, or both. When that held, the Kavu was a tidy combat blowout. When it did not, the trigger simply never fired, and a 2/2 for three was all you got.