Smeargle

Smeargle is somewhat of an anomaly in the world of competitive Pokemon. It has the lowest BST of all OU--and even UU--Pokemon, and seems it like it could do something by having a movepool that quite literally expands ad infinitum. Knowing every single move in the game and having a decent Speed stat potentially gives it a niche as a disabler, as it is faster than common leads such as Azelf and Aerodactyl with a Choice Scarf and then can put something to sleep, set up entry hazards, pivot out with U-turn, or ruin a wall with Trick. With access to rare support moves like Lunar Dance, Rapid Spin, and Spikes, Smeargle can provide unpredictable support for hyper offensive teams that other leads such as Skarmory and Roserade fail to provide.

Unfortunately, those abysmally low stats truly do haunt Smeargle, and as a result, it struggles to adapt to the lead metagame. Smeargle's defensive stats are so low it cannot switch into any attack it isn't immune to and, as such, is almost solely used as a lead. Smeargle is much more reliant on what the opponent leads with than most other leads: Smeargle cannot deal with opposing Pokemon with a Lum Berry such as Metagross, Machamp, and some Azelf, as it has almost no offensive presence without Spore. Additionally, while it is fast enough for slower leads such as Hippowdon and Swampert, it needs a Choice Scarf to avoid getting shut down completely by Azelf, Aerodactyl, Roserade, Choice Scarf Breloom, and Taunt Heatran. However, if it does not hold a Focus Sash, it simply gets OHKOed by almost any attack, meaning foes can just stay in and wait to wake up. While Smeargle has access to every valuable support move, with the pace of the metagame, it struggles to use more than one or two moves after it puts something to sleep, especially if it is locked into Spore. Above all of this, if Smeargle's entry hazards get spun away, all of its work is for naught. While Smeargle can adapt to specific leads, such as using Counter + Focus Sash in tandem with Own Tempo to KO Machamp, Explosion to deny Rapid Spin and heavily weaken offensive Pokemon like Latias, and Trick Room + Endeavor to take advantage of offensive Pokemon without priority, it struggles to have a universal set to perform against most leads. Because of this, it is relegated to the bottom of DPP OU as an unconventional lead not recommended for most games.