Whiscash

Whiscash has access to the uncommon Dragon Dance, which it can use quite effectively to sweep late-game thanks to its good bulk and great defensive typing that leaves it with just one weakness. However, it faces competition from Samurott and Carracosta as a boosting sweeper, as the former is also bulky, has better offensive stats, and has access to Aqua Jet to beat faster threats and Megahorn to destroy Grass-types, and the latter can use Shell Smash to become an immediate threat. Whiscash is also quite slow—many Pokemon and almost every Choice Scarf user outspeed it even after a Dragon Dance boost—and its Attack is average, meaning it will need a few boosts in order to become a threatening sweeper.