Raticate

A cursory glance at Raticate may lead one to quickly disregard it as simply a worse Persian. Indeed, the cat and mouse share many similarities such as a Normal typing and access to Thunderbolt and Bubble Beam to strengthen specific matchups, but Raticate suffers from worse attacking stats and a significantly worse Speed tier. However, Raticate has a distinct niche thanks to its exclusive access to Super Fang. RBY OU is a metagame where KO ranges are a crucial factor for players to keep in mind, as nothing wants to be in range of an enemy Tauros. Super Fang's consistent damage is incredible for getting foes to these KO ranges and is guaranteed to leave a dent in anything that attempts to switch in; most importantly, Super Fang ignores type immunity against Gengar, which is one of Raticate's major strengths over Persian, as it limits the number of times that Gengar can switch in safely. Against frailer or weakened targets, Raticate can also threaten them with a Hyper Beam afterwards to KO; additionally, with its great base 97 Speed, it outpaces many Pokemon in the metagame, such as Jynx, Cloyster, and Articuno, and threatens them with massive damage.

Unfortunately, it's not all cheddar and fruit for this humble rodent. Raticate is incredibly frail, making it difficult to switch in and repeatedly wear down foes. This, combined with Super Fang's 89.5% accuracy and 16 PP, can allow faster foes like Starmie and Alakazam with reliable one-turn recovery moves to stall out Raticate's Super Fangs until it misses or runs out of PP. Raticate isn't just frail, either: its defensive profile is decidedly mediocre, meaning it can't afford to trade blows often and thus often loses a flat one-on-one fight; Super Fang's imperfect accuracy also means that missing an attack will force Raticate to take a potentially fatal blow in return, something it cannot afford. Finally, Raticate's attacking stats are very average, which often prevents it from KOing bulkier foes even after a Super Fang. As a result of these flaws, Raticate is heavily reliant on good prediction to be effective in its role, and as such, it is not recommended for most RBY OU teams because Tauros is normally all that's necessary. Even if a "second Tauros" is desirable, Persian is usually the better choice.