Koma, World-Eater is a rare Legendary Creature — Serpent card from Foundations (FDN), collector number 480. Current market price: $1.32 (foil $2.13), TCGplayer market prices via Scryfall.
This spell can't be countered. Trample, ward {4} Whenever Koma deals combat damage to a player, create four 3/3 blue Serpent creature tokens named Koma's Coil.