Jumpluff

While Jumpluff's very low base Attack doesn't scream "good offensive Pokemon", it is a fantastic Pokemon in the PU metagame for a variety of reasons. First, its great Speed and amazing movepool, which features options such as Sleep Powder, U-turn, and Swords Dance, make it a very versatile Pokemon that can provide tons of utility to nearly every team. Jumpluff can perform several important roles quite effectively. In addition to being a solid utility Pokemon in general, Jumpluff also makes for a great partner to the many threatening setup sweepers in PU thanks to its access to Sleep Powder and Memento, and it can even sweep itself with Swords Dance. However, Jumpluff's low base Attack, while somewhat mitigated by its high-Base Power STAB moves and decent coverage, makes it quite easy to switch into, especially after it has already put a foe to sleep. The Swords Dance set is easily checked by common Pokemon such as Floatzel, Zebstrika, and most Choice Scarf users. Jumpluff is also worn down quite quickly due to its Stealth Rock weakness, which can be difficult to account for in PU due to the metagame's limited number of options for entry hazard removal.