Monastery Mentor is a mythic Creature — Human Monk card from March of the Machine Promos (PMOM), collector number 28p. Current market price: $0.81 (foil $1.64), 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.