Lavacore Elemental is a uncommon Creature — Elemental card from Planar Chaos (PLC), collector number 103. Current market price: $0.19 (foil $0.40), TCGplayer market prices via Scryfall.
Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.) Whenever a creature you control deals combat damage to a player, put a time counter on this creature.