Jokulmorder is a rare Creature — Leviathan card from The List (PLST), collector number CSP-37. Current market price: $0.65, TCGplayer market prices via Scryfall.
Trample This creature enters tapped. When this creature enters, sacrifice it unless you sacrifice five lands. This creature doesn't untap during your untap step. Whenever you play an Island, you may untap this creature.