|Evolves from||Beedrill (Beedrillite)|
When Beedrill Mega Evolves into Mega Beedrill, it gains more defined features. The antennae are shorter and now extent forward and back over its head. Its eyes become longer and sleeker. It now has three pairs of wings; the uppermost pair is larger with a black trim along the top. Its stingers become longer and larger, resembling javelins. Its legs are no longer insectoid, and instead resemble conical, black-and-yellow stingers with white tips. Its abdomen becomes larger and grooved, and is attached to its thorax by a black structure. A similar black structure connects its head and thorax. The stinger on its abdomen is now a pale yellow, and it now has black stripes over its entire body.
Fast-acting poison is stored in the stingers on Mega Beedrill's limbs, while the tail stinger produces a slow-acting poison that is used to finish opponents. The instantaneous poisons are instead used to prevent the foe from fleeing.