Relicanth

Although it's seen as "just another Rock-type" by many, Relicanth has several positive niches that make it a strong Pokemon. It is faster than most other Rock-type Pokemon, has usable Attack, and has splendid physical bulk. In comparison to Aggron, its Water sub-typing makes it less susceptible to Ground-type Pokemon. Relicanth's Water / Rock typing also grants it a useful dual resistance to Fire, along with resistances to Normal, Flying, Ice, and Poison. Movepool-wise, Relicanth has access to a variety of moves that offer great coverage and support. However, the main selling point of using Relicanth is its access to Head Smash, which, when combined with Rock Head, makes for a deadly sweeper.

It's not all sunshine for Relicanth though. Relicanth's horrible Special Defense stat makes it unlikely to live through several neutral special attacks. That poor Speed in comparison to the rest of the metagame makes you want to gouge your eyes out. It also comes with a dual weakness to Grass, as well as weaknesses to Fighting, Ground, and Electric. Nevertheless, Relicanth can be one of the most devastating Pokemon in a blink of an eye.