I vesuviani

A fisherman who lives in the Rione Terra of Pozzuoli, catches a polyp that at night is transformed into a sensuous woman. An odd black prince who claims to be the brother of the unfortunate woman tells the fisherman about the sad fate to which she has been condemned by a magic spell. But the polyp, which has taken lodging in a tub and at night visits Toritore's bed, in spite of it all will ultimately meet her fate in a frying-pan. (imdb)