Giant's Boulder is a common Artifact card from The Hobbit (HOB), collector number 173. Current market price: $0.21 (foil $0.86), TCGplayer market prices via Scryfall.
When this artifact enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.) {1}, {T}: Add one mana of any color. {7}, {T}, Sacrifice this artifact: Destroy target permanent.