Frillscare Mentor is a uncommon Creature — Human Warrior card from Ikoria: Lair of Behemoths (IKO), collector number 121. Current market price: $0.22 (foil $0.32), TCGplayer market prices via Scryfall.
When this creature enters, put a menace counter on target non-Human creature you control. (It can't be blocked except by two or more creatures.) {2}{R}, {T}: Put a +1/+1 counter on each creature you control with menace.