Thrun, the Last Troll is a mythic Legendary Creature — Troll Shaman card from Mirrodin Besieged (MBS), collector number 92. Current market price: $0.83 (foil $12.02), 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.