Mega Charizard Y

Mutate {4}{w}{r}(If you cast this spell for its mutate
cost, put it over or under target non-Human creature
you own. They mutate into the creature on top plus
all abilities from under it.)
Flying, haste
Other red creatures you control get +2/0.
Whenever this creature mutates, if it mutated
onto Charizard, untap all creatures that attacked
this turn. After this phase, there is an additional
combat phase, followed by an additional
main phase.