Silvergill Mentor (#69)

Type: Creature — Merfolk Wizard

Text: As an additional cost to cast this spell, behold a Merfolk or pay {2}. (To behold a Merfolk, choose a Merfolk you control or reveal a Merfolk card from your hand.)
When this creature enters, create a 1/1 white and blue Merfolk creature token.

Set: Lorwyn Eclipsed (#69)