Curious Inquiry is a uncommon Enchantment — Aura card from Murders at Karlov Manor (MKM), collector number 51. Current market price: $0.29 (foil $0.26), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, investigate." (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")