Crystal Skull, Isu Spyglass is a rare Legendary Artifact card from Assassin's Creed (ACR), collector number 158. Current market price: $2.76 (foil $3.71), TCGplayer market prices via Scryfall.
You may look at the top card of your library any time. You may play historic lands and cast historic spells from the top of your library. (Artifacts, legendaries, and Sagas are historic.) {T}: Add {U}.