Koma, Cosmos Serpent is a mythic Legendary Creature — Serpent card from Kaldheim Promos (PKHM), collector number 221s. Current market price: — (foil $16.69), TCGplayer market prices via Scryfall.
This spell can't be countered. At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil. Sacrifice another Serpent: Choose one — • Tap target permanent. Its activated abilities can't be activated this turn. • Koma gains indestructible until end of turn.