Clamperl

Clamperl is a clam-like Pokemon with a pearl-like Pokemon. It is a pure Water type Pokemon.

Clamperl has a unique evolution as it can evolve into 2 forms: Gorebyss, a pure Water type and Huntail, a Water/Dark type. It can evolve into Gorebyss by trading it when it's holding a Deep Sea Scale. It can evolve into a Huntail by trading it away when it's holding a Deep Sea Tooth.