Sea Monsters are seen in Studio Ghibli's film Ponyo on the Cliff by the Sea directed by Hayao Miyazaki of Studio Ghibli.
They are summond by Fujimoto to look for Ponyo. They weak creatures, because they get easily beaten by Ponyo's Sisters, who just drink them up, becuase they are made out of water. Sea monsters are slow and they can't move beyond the sea.