Its legs have become poison stingers. It stabs its prey repeatedly with the stingers on its limbs, dealing the final blow with the stinger on its rear.
– Pokémon Let’s Go Eevee/Pikachu Pokédex
Mega Beedrill is introduced in ORAS. Beedrill is an odd Pokemon to get a Mega, especially since its counterpart, Butterfree, didn’t get one.
Its typing remains Bug/Poison, but its ability becomes Adaptability, which increases STAB moves from 1.5x to 2x.
Stat-wise, Mega Beedrill is super min-maxed. Its Attack is increased by 60 to 150, and its Speed is increased by 70
to 145. Its defenses don’t change, and it actually has less Sp Attack. So even though it only has a BST of 495, they’re distributed to make Mega Beedrill a physical glass cannon. It has the highest Attack and Speed of Poison type Pokemon. It also has the least Defense of all Mega Pokemon.