Raging Ravine is a rare Land card from Edge of Eternities: Stellar Sights (EOS), collector number 35. Current market price: $0.40 (foil $0.80), TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add {R} or {G}. {2}{R}{G}: Until end of turn, this land becomes a 3/3 red and green Elemental creature with "Whenever this creature attacks, put a +1/+1 counter on it." It's still a land.