When it Mega Evolves, it becomes more vicious than ever before. Some say that’s because its excess of power is causing it pain.
– Pokemon Moon Pokédex
Wow, this Moon Pokedex entry is brutal. Now you’re gonna feel bad when you mega evolve Aerodactyl.
Aerodactyl becomes even more spiky when it mega evolves, and gains some pretty cool rock beard. Aerodactyl is already fast, but Mega Aerodactyl becomes even faster. It ties with Mega Alakazam and Electrode at 150 base Speed, making it the 4th fastest Pokemon (behind Spd Deoxys, Ninjas, and Pheramosa)