Quagsire

Quagsire has always been a competent defensive Ground-type. However, it's generally not thought of as a top OU Pokemon because its ability to counter Hidden Power legends was not needed when they were banned and because it's a lot less offensive than other Ground-types. However, in the modern metagame where the legendary Electric-types regularly carry Hidden Power, Quagsire's neutralities to Ice- and Water-type attacks give it a unique defensive advantage over other Ground-types, although the uncommon Hidden Power Grass can still be used to ruin it. Quagsire is a decent mixed wall that can threaten to sweep if given the chance to set up a Belly Drum, but unlike other Ground-types such as Nidoking and Marowak, it doesn't have the attacking stats to pose an immediate offensive threat.