Yes, the Spanish dancer is indeed a slug! Image credit: Ewout Knoester
The Spanish dancer got its name for its graceful and coordinated rhythmic movements that are reminiscent of the undulations of a Spanish flamenco dancer’s red skirt. And it can really dance!
When the Spanish dancer needs to get about in a hurry, it swims (usually when threatened). However, due to the absence of bones and significant fins, it has limited choices for movement. So it uses its mantles, which it normally holds in an inwardly curled position, to provide propulsion with an undulating movement that results in a rather meaty acceleration.