FusionDex

During mating season, hordes of Volin gather together in the dark of night and demonstrate their glowing oral cavity to one another. The wider one can open its mouth and the brighter it glows, the more attractive Volin is to its fellows.

This Pokémon's stomach fluid can even digest scrap iron. With their taillights lit, Volin fly in a swarm, drawing geometric designs in the night sky.