Disturbed Slumber is a common Instant card from The Lost Caverns of Ixalan (LCI), collector number 182. Current market price: $0.15 (foil $0.22), TCGplayer market prices via Scryfall.
Until end of turn, target land you control becomes a 4/4 Dinosaur creature with reach and haste. It's still a land. It must be blocked this turn if able.