Creeping Tar Pit is a mythic Land card from Ultimate Box Topper (PUMA), collector number U34. Current market price: — (foil $3.96), TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add {U} or {B}. {1}{U}{B}: Until end of turn, this land becomes a 3/2 blue and black Elemental creature. It's still a land. It can't be blocked this turn.