Mew

Mew is recommended to feature on all of your RBY Ubers teams and is one of only two Uber Pokemon—Pokemon banned from standard first generation play dating back to the earliest Nintendo sponsored tournaments. The mythical Pokemon may learn every TM, but it is uncommon in high-level play to see it without Swords Dance. Mew is the tier's premier physical sweeper; its base 100 stats all around let it outspeed Jynx and Speed tie with Zapdos, have an unboosted Attack stat equivalent to Tauros, and have bulk rivaling Snorlax's. Additionally, Soft-Boiled can capitalize on Mew's impressive bulk and Reflect can enhance it, which also makes Mew one of the top physical walls in the tier; conversely, it can sacrifice itself with Explosion to hopefully take another high-value Pokemon down with it. As a Special sweeper, it is outclassed by its clone, Mewtwo, which has Amnesia and a far superior Special stat, as well as by Amnesia Slowbro. Also, Mew's wallbreaking tool, STAB Psychic, is weaker than Alakazam's and Exeggutor's Psychics due to their higher Special stats.