Thrun, the Last Troll is a mythic Legendary Creature — Troll Shaman card from Secret Lair Drop (SLD), collector number 810. Current market price: $1.52, TCGplayer market prices via Scryfall.
This spell can't be countered. Hexproof (This creature can't be the target of spells or abilities your opponents control.) {1}{G}: Regenerate Thrun.