Toon Copycat

Indestructible, Slapstick X

When Toon Copycat enters the battlefield, choose one non toon creature your opponent controls. This becomes a copy of target creature, except it is a toon along with it's other types and is not a legendary. When the original target creature dies, Toon Copycat is moved to the original
owner's graveyard.

Slapstick is X, where X is the mana cost of the original creature.