Riveting Rigger is a common Artifact Creature — Cyborg Rigger card from Unstable (UST), collector number 19. Current market price: $0.07 (foil $0.24), TCGplayer market prices via Scryfall.
When this creature enters, you may sacrifice another artifact. If you do, put two +1/+1 counters on this creature and it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)