Witness of the Ages is a uncommon Artifact Creature — Golem card from Khans of Tarkir (KTK), collector number 228. Current market price: $0.04 (foil $0.40), TCGplayer market prices via Scryfall.
Morph {5} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)