Reedfish fakemon.

Ropearl are "living fossils" similar to Relicanth who were once much larger and more dangerous, the only thing that has changed about them in the years has been their size, adapting to smaller and smaller areas of muddy water as habitats in the region shrank. Bichimu are Ropearl who have lived for hundreds and hundreds of years and have become enlightened. They're usually only seen travelling with trainers, and in some areas it's tradition to pass Ropearl and Bichimu down to the eldest child in a trainer/breeder/ranger family.

Water and Water/Dragon Ropearl is found uncommonly in swampy areas (and can also be pulled up from rivers at a higher rate using the Super Rod.) Levels up with Calm Mind in moveset (he gets it naturally at level 42, but it's also a TM, as always.)

Abilities are Cloud Nine and Marvel Scale, and Drizzle is the hidden.