FusionDex

It senses when spirits are low on sailing vessels and appears to lead the sailors in riveting, uproarious shanties, uplifting their morale. For this, it almost always expects a small share of the ship's coffers, which it stores in its chest.

When it hears festive music, all the cells in its body become stimulated, and it begins moving in rhythm. The soul of seaweed adrift in the waves became reborn as this Pokémon.