Aerodactyl

Aerodactyl finds a niche on defensive teams in Ubers for its ability to completely stonewall standard Mew and Snorlax sets as well as some variants of Tauros thanks to its unique Rock / Flying typing. Once it sets up Reflect, it takes negligible damage from even a +6 Mew Body Slam. Aerodactyl is also gifted with an exceptional base 130 Speed, which gives it a sky high 25.39% critical hit rate and ties it with Jolteon and Mewtwo as the second fastest Pokemon in the game.

However, Aerodactyl's flaws massively outweigh its benefits. Its damage output is mediocre at best, struggling to threaten strong special attackers such as Mewtwo and Slowbro even on a critical hit, while it gets 2HKOed or 3HKOed in return by most special attacks; this lets Mewtwo and Slowbro switch in with little issue. Aerodactyl also cannot meaningfully threaten physical attackers outside of trying to burn them with Fire Blast, which is extremely risky, as it risks accidentally burning a special attacker switching in. Aerodactyl's movepool is extremely shallow, forcing it to run Double-Edge as its main attacking option, and recoil combined with stray hits from Mew and Snorlax wears it down quickly. This chip damage will eventually force it to use Rest, and while it may be able to do so safely against standard Mew and Snorlax, it's forced out by strong special attackers, such as Mewtwo, Slowbro, and Starmie. Once forced out while asleep, Aerodactyl has difficulty getting back in safely due to its frailty and passivity.