Restless Ridgeline is a rare Land card from The Lost Caverns of Ixalan Promos (PLCI), collector number 283p. Current market price: $1.10 (foil $0.35), TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add {R} or {G}. {2}{R}{G}: This land becomes a 3/4 red and green Dinosaur creature until end of turn. It's still a land. Whenever this land attacks, another target attacking creature gets +2/+0 until end of turn. Untap that creature.