Thornling

The mono-green answer to Morphling, built by translating that blue mana-sink shapeshifter into green's vocabulary of speed and resilience. The two cards rhyme deliberately: both are five-mana shapeshifters with a fistful of single-mana activations that turn open lands into combat advantage. Where Morphling bought its flexibility through evasion and untargetability against burn and removal, this one buys survival a different way: haste means the body threatens the turn it lands, trample means a single chump-blocker cannot blunt the damage, and indestructible means it walks through a wrath or a damage-based kill spell. The generic-cost abilities are the clever part. The standard green plan of growing a creature is split into a power-up and a toughness-up that move stats in opposite directions, so at instant speed you can either push extra damage through a block or sandbag toughness to survive a burn spell or a fight, choosing the shape after the opponent commits. Open mana is the only real restriction, and that is exactly green's strength: a deck flooded with lands turns this into a creature that beats damage-based removal, forces trample damage past chump-blockers, and swings hard in a single turn. The modest base stats were never the point; the ceiling, with five or six lands untapped and a window to respond, is the whole design.