Scrap Trawler is a rare Artifact Creature — Construct card from Aether Revolt Promos (PAER), collector number 175s. Current market price: — (foil $3.63), TCGplayer market prices via Scryfall.
Whenever this creature dies or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.