Lullmage Mentor is a rare Creature — Merfolk Wizard card from Zendikar (ZEN), collector number 54. Current market price: $8.12 (foil $19.83), TCGplayer market prices via Scryfall.
Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token. Tap seven untapped Merfolk you control: Counter target spell.