Krosan Colossus is a rare Creature — Beast card from Onslaught (ONS), collector number 270. Current market price: $0.40 (foil $12.31), TCGplayer market prices via Scryfall.
Morph {6}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)