Volbeat

Volbeat isn't a Pokemon that seems very viable due to its pitiful stats, but a closer look reveals that it has access to the rare Prankster ability, which is where its main niche lies. It has all the right moves to utilize its ability as well, although the lack of Taunt really hinders it. Despite that, Volbeat makes for a great rain setter and also supports rain teams with paralysis support in the form of priority Thunder Wave. Volbeat also has a rare boosting move in Tail Glow, which it can effectively pass onto another Pokemon with priority Baton Pass, and priority Encore makes setting up against the likes of entry hazard leads and opposing boosting Pokemon easier. Unfortunately, Volbeat has low bulk and an even lower offensive presence, making setting up and passing a difficult task. Furthermore, its Bug typing is a double-edged sword; it gives Volbeat resistances to Fighting and Ground, but also burdens it with weaknesses to the omnipresent Fire- and Rock-type attacks. It faces a lot of competition from Liepard as a rain setter and Smeargle as a Baton Passer, as the former lacks a Stealth Rock weakness and the latter has a superior boosting move in Quiver Dance.