Tokka & Rahzar, Terrible Twos (Teenage Mutant Ninja Turtles)

Legendary Creature Ñ Turtle Wolf Mutant - This spell can't be countered.
Menace
Whenever a player casts a spell, if the amount of mana spent to cast it was less than its mana value, Tokka & Rahzar deal 3 damage to that player.