Slowbro

In a time where Mewtwo ravaged the RBY Ubers landscape and players desperately searched for a good check to it, Slowbro came to answer the call. Slowbro's Amnesia set, known as "TobyBro" and first created by Wintermute in the early 2000s, is the best check to non-Thunderbolt Mewtwo in the tier while being a very strong Pokemon in its own right. Amnesia, along with a great typing and excellent bulk, gives Slowbro immense sweeping potential. A boosted Surf is capable of OHKOing or 2HKOing almost everything in the tier, and even resistant foes are 3HKOed. Amnesia also helps Slowbro patch up its Electric weakness, since Special is used for both offense and defense. Slowbro can even use Thunder Wave to fix its miserable Speed, and it can also reapply the foe's Speed drops from paralysis by using Amnesia.

However, Slowbro will take very heavy damage from a critical hit Thunderbolt regardless of boosts, forcing it to use Rest earlier, and many Electric-type Pokemon have very high critical hit rates courtesy of their high Speed. Slowbro's abysmal Speed, while mitigated by Thunder Wave, can give it trouble as it tries to boost against faster threats while also necessitating some amount of paralysis support from teammates. Slowbro is also very one-dimensional and predictable; however, it will always be one of the most dangerous sweepers, no matter how much the opponent might know it is coming.