Skeletonize is a uncommon Instant card from Shards of Alara (ALA), collector number 114. Current market price: $0.11 (foil $0.40), TCGplayer market prices via Scryfall.
Skeletonize deals 3 damage to target creature. When a creature dealt damage this way dies this turn, create a 1/1 black Skeleton creature token with "{B}: Regenerate this token."