Taillow

With two useful abilities in Guts and Scrappy and an excellent base 85 Speed stat that allows it to hit the coveted 19 Speed tier, Taillow is able to take advantage of its ridiculously high-powered STAB attacks such as Brave Bird and Boomburst to act as a potent offensive threat. U-turn allows Taillow to play around its checks, and the ability to viably run either a physical or special set means that Taillow isn't totally one-dimensional.

However, despite its strengths, Taillow is actually quite easy to take down. Its bulk is absolutely atrocious; this is further compounded by its weakness to Stealth Rock. Moreover, despite the power of Taillow's STAB moves, its coverage moves are much less impressive, being limited in quantity and generally quite underwhelming. Although Taillow has its niche, its enormous flaws hold it back from being a top-tier threat.