Failed Conversion is a common Enchantment — Aura card from March of the Machine (MOM), collector number 103. Current market price: $0.07 (foil $0.15), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets -4/-4. When enchanted creature dies, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)