Anzrag, the Quake-Mole is a mythic Legendary Creature — Mole God card from Murders at Karlov Manor (MKM), collector number 186. Current market price: $8.14 (foil $7.26), TCGplayer market prices via Scryfall.
Whenever Anzrag becomes blocked, untap each creature you control. After this phase, there is an additional combat phase. {3}{R}{R}{G}{G}: Anzrag must be blocked each combat this turn if able.