Qwilfish

Qwilfish (Japanese: ハリーセン Harysen) is a dual-type Water/Poison Pokémon introduced in Generation II.
In Hisui, Qwilfish has a dual-type Dark/Poison regional form. Hisuian Qwilfish evolves into Overqwil in Hisui after using Barb Barrage in the strong style at least 20 times. Johtonian Qwilfish is not known to evolve into or from any other Pokémon, nor is Hisuian Qwilfish known to in other regions.