Aerodactyl

Aerodactyl is one of the most feared Choice Band users in OU. Its standard combination of attacks in Rock Slide, Double-Edge, and Earthquake is unresisted, allowing the prehistoric tyrant to ravage the OU metagame. Aerodactyl's secondary Flying typing blesses it with an immunity to Earthquake and, more importantly, Spikes, allowing it to hit hard throughout the match. Finally, as if it could get any better for Aerodactyl, it's tied for the fastest Pokemon in ADV OU with Jolteon, which is OHKOed by Earthquake. Unfortunately, Aerodactyl's weakness to Ice Beam, Surf, Rock Slide, and other common moves in the ADV OU metagame prevent it from switching in as often as one would hope. Additionally, Aerodactyl's defenses are far from stellar; even non-STAB super effective moves will do significant damage to Aerodactyl, if not OHKO it outright.