Wabbajack

Whenever you cast an instant or sorcery, you may
pay {1}. If you do, choose one — Wabbajack becomes a random effect until end of turn:

Wabbajack turns into a creature with power and toughness equal to the number
of spells you cast this turn.Wabbajack deals damage equal to the number of spells you cast this turn to
any target.Wabbajack creates a token that's a copy of another target permanent you control until end of turn.