Rancor is a common Enchantment — Aura card from Urza's Legacy (ULG), collector number 110. Current market price: $1.52 (foil $55.85), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets +2/+0 and has trample. When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.