With Beedrill getting a Mega Evolution, it only makes sense to allow Butterfree to have one of it's own. I took a lot of inspiration from it's Gigantamax form when making the design.
Mega Butterfree becomes part psychic type, fitting the solid psychic coverage it gets. That, combined with it's massive special attack boost, makes Mega Butterfree a valuable member of any team.
by AsterMachina