Sandslash

Sandslash is often overlooked in RBY OU, but it realizes a dangerous niche with its unique combination of typing, movepool, and Speed tier. After a Swords Dance, Sandslash can 2HKO every Pokemon in the tier, and it is just fast enough to outpace many crucial threats, including Rhydon, Chansey, and Exeggutor. As a Ground-type, it is frailer than Rhydon and Golem, less powerful to start, and doesn't resist Normal, making it a poor pivot. However, it can sweep, is faster, and beats the two one-on-one by virtue of its Ground neutrality. As a Swords Dance user, its winning matchup against Rhydon, Electric immunity, and consistent STAB Earthquake make up for its lower offensive stats. In particular, its Thunder Wave immunity provides both a consistent entry point for sweeping and a partial safeguard against sweep-ending paralysis, a weakness that plagues all other viable Swords Dance users. Overall, though, Sandslash is frequently defined by its shortcomings. No Normal or Flying resistance means it can't be a primary physical tank or a firm Zapdos answer, unlike Rhydon or Golem. It has low Speed, low Special, a plethora of weaknesses, and merely respectable power before setup, which leave it easily forced out and picked off. Most notably, the excellent Starmie can harry it in all stages of a battle. Unlike all other viable Swords Dance users, it misses the crucial OHKO on Chansey after a boost. Still, with paralysis support and against slower teams, Sandslash can be a very potent offensive weapon while checking Rhydon, Zapdos, Jolteon, and Golem in emergencies.