Creeping Tar Pit is a rare Land card from Edge of Eternities: Stellar Sights (EOS), collector number 54. Current market price: $2.50 (foil $3.05), 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.