Sevant, Splicer Prodigy

Creature cards in your hand have mutate where
the mutate cost is equal to their casting cost.
Mutated creatures you control have the combined colors, types, subtypes, power, and toughness of themselves and creatures mutated onto them.
{1}{g/u}{g/u}{t}: Exile a creature you control and return
it to the battlefield mutated under target creature
you control.