Monastery Mentor is a mythic Creature — Human Monk card from The List (PLST), collector number FRF-20. Current market price: $3.68, TCGplayer market prices via Scryfall.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Whenever you cast a noncreature spell, create a 1/1 white Monk creature token with prowess.