Mollusque-Lanceur (French for "Mollusk Launcher"; also referred to as Brigadier Mollusque-Lanceur III, Dauphin of Bubblaine) is a giant, well-dressed, purple Gushen who is a boss in Super Mario Odyssey. He is presumably related to the similar-looking cosmic creatures called Astro-Lanceurs.
He initially appears atop the large glass chalice in the Seaside Kingdom, sucking the Sparkle Water from it with a bendy straw, driving tourists away. In order to stop him, Mario must hit several glass case-protected Ground-Pound Switches scattered throughout the kingdom, which will cause a giant cork to be shot onto his head. Mollusque-Lanceur will attempt to stop him by launching Spiked Shells that explode after a short period into the water near Mario. Once Mollusque-Lanceur has taken enough damage, he will leave the tower to confront Mario directly, now with a large puddle of lava on his head, and without his hat.
In battle, Mollusque-Lanceur swims around, occasionally spitting a Spiked Shell or drill-like cone shell. To defeat him, Mario must capture a Gushen and use its water to clear the lava off of his head, exposing it. From there, Mario can either keep pounding his head with the water, or Ground Pound his head, until eventually, he is defeated. However, he can spin to escape Mario's attacks for a brief moment. When he is defeated, Mario, in his normal state will appear on top of Mollusque-Lanceur's head, which rapidly begins to inflate and glow, before violently exploding, sending Mario and the Multi Moon flying over the chalice, where they are suspended by its Sparkle Water.
The rematch in the Mushroom Kingdom takes place in the sky instead of the ocean. There is only a single Gushen for Mario to capture and one piece of solid ground. Mario must remain in the air at all times as he fights Mollusque-Lanceur again, but because it is constantly raining in the area, the Gushen has an infinite water supply and it refills at all times.
Names in other languages