Innocuous Researcher is a rare Creature — Centaur Detective card from Murders at Karlov Manor Commander (MKC), collector number 348. Current market price: $0.23, TCGplayer market prices via Scryfall.
Parley — Whenever this creature attacks, each player reveals the top card of their library. For each nonland card revealed this way, you investigate. Then each player draws a card. At the beginning of your end step, you may untap all lands you control. If you do, you can't cast spells until your next turn.