Professor Fernandez is studying the metamorphosis in living organisms to cure his daughter of a strange disease that occurs in full moon nights.
| Actor | Role |
|---|---|
 Kitty de HoyosClarisa Fernandez | Clarisa Fernandez |
 Joaquín CorderoDr. Alejandro Bernstein | Dr. Alejandro Bernstein |
 Columba DomínguezMarcela de Fernandez | Marcela de Fernandez |
 José Elías MorenoProfessor Fernandez | Professor Fernandez |
 Roberto CañedoDr. González | Dr. González |
 Noé MurayamaCazador de Lobos | Cazador de Lobos |
 Adriana RoelAlicia Fernandez | Alicia Fernandez |
 Crox AlvaradoCrumba | Crumba |
 Ramón BugariniInspector | Inspector |
 Hortensia SantoveñaHousemaid | Housemaid |
| JJudith DupeyrónAdelita | Adelita |
 Jorge RussekCommissioner | Commissioner |
| MMargarita DelgadoNot listed | Not listed |
| JJosé Dupeyrón(uncredited) | (uncredited) |