Gastrodon

Gastrodon's excellent defensive typing allows it to check prominent threats in the tier such as Steelix, Aggron, and Swords Dance Charizard. Furthermore, Storm Drain gives it a Water immunity, allowing it to check Pokemon such as Lanturn, Kabutops, and Floatzel a lot more easily. It makes for a nice Scald and Volt Switch absorber thanks to its ability and its secondary Ground typing, while having access to Recover also means that Gastrodon can continually pivot throughout the match. Sadly, it is very slow, meaning it has to take a hit before firing back. It is also very susceptible to status, making it prone to being worn down and potentially forcing it to use Recover more often than it would like. It also isn't the best Fire-type check, since Fire-types such as Magmortar and Pyroar tend to carry Grass-type coverage for it and other targets such as Rhydon. Grass-types in general such as Gourgeist-XL, Vileplume, and Lilligant are a pain for Gastrodon, as they resist its STAB moves and can OHKO with their own.