Golbat

As a guaranteed means of removing entry hazards, Defog is one of the most important moves in the RU metagame—and as a fairly bulky Pokemon with a good defensive typing and a reliable recovery move, Golbat is one of its best users. It also has serious utility with Infiltrator Toxic, which allows it to cripple threatening boosters such as SubCM Meloetta right through their Substitutes, as well as Super Fang and Taunt, which let it wear down Steel-types like few others and take on defensive Pokemon and hazards users, respectively. Although Golbat walls Grass-types quite well and takes on Fighting-types pretty well with a STAB Brave Bird, its typing unfortunately leaves it open to being hit super effectively by a whole heap of strong offensive types, specifically Electric, Ice, Rock, and Psychic. While Golbat is capable of tanking hits and Defogging away hazards, it often lets entry hazard users, especially the prominent Mega Steelix and Rhyperior, switch back in and reset their hazards, and it certainly can't come in on them to Defog; it also lets most Steel-types do whatever they want, though Taunt and Super Fang generally help in these regards. Because Golbat is weak to the Stealth Rock it is tasked with removing, and because the Fighting-types it walls often carry Knock Off to remove its Eviolite and thus slash its defenses, Golbat can be hard-pressed to stay alive and keep doing its job, but it can definitely fill the needs of your team if used correctly.