Reprobation is a common Enchantment — Aura card from Modern Horizons (MH1), collector number 23. Current market price: $0.28 (foil $3.06), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature loses all abilities and is a Coward creature with base power and toughness 0/1. (It keeps all supertypes but loses all other types and creature types.)