Orthworm

Earth Eater converts Ground moves into HP recovery. Orthworm is healed by Mega Garchomp's Earthquake rather than damaged, creating an unconditional Ground immunity that enables Earthquake spam. Iron Defense doubles Defense in one turn for rapid Body Press damage accumulation. Body Press scales with Defense for offensive presence while building survivability. Heavy Slam deals damage scaling with Orthworm's weight. Impish with calibrated Defense and Special Defense investment creates mixed bulk. Leftovers sustains. Earth Eater is the entire reason for this slot. Partnering with Earthquake spam requires Ground immunity, and Earth Eater turns each Earthquake into healing rather than chip damage.