Nidoking and its female counterpart Nidoqueen share their category name with Rhydon and Rhyperior. They are all known as the Drill Pokémon. Additionally, all four are partly Ground types.
Although its female counterpart Nidoqueen cannot be bred, Nidoking can.
Nidoqueen and Nidoking are the only Pokémon with a Poison/Ground type combination.
Nidoking is a popular choice with anime rivals as both of Ash's main rivals (Gary and Paul) have one as well as Jimmy's main rival.
