Golgari Grave-Troll is a rare Creature — Troll Skeleton card from Ultimate Masters (UMA), collector number 167. Current market price: $2.12 (foil $5.21), TCGplayer market prices via Scryfall.
This creature enters with a +1/+1 counter on it for each creature card in your graveyard. {1}, Remove a +1/+1 counter from this creature: Regenerate this creature. Dredge 6 (If you would draw a card, you may mill six cards instead. If you do, return this card from your graveyard to your hand.)