Prototype X-8 is a mythic Legendary Artifact Creature — Robot Octopus card from Alchemy: Edge of Eternities (YEOE), collector number 24.
This spell costs {2} less to cast for each creature card in your graveyard. Whenever another creature you control enters, if you cast it, sacrifice it. Conjure a duplicate of it onto the battlefield. The duplicate perpetually becomes a Robot artifact in addition to its other types.