Tam, the Possibility is a rare Legendary Creature — Gorgon Wizard card from Reality Fracture Promos (PFRA), collector number 276p.
Planeswalker spells you cast cost {1} less to cast. {W}{U}{B}{R}{G}, {T}: Proliferate X times, where X is the number of planeswalker types among planeswalkers you control. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there.)