The legendary Loreley has been living for centuries in a grotto beneath the river Rhein in Germany. Every night when the moon is full, she turns into a reptile-like creature craving for human blood. When one girl after another of a nearby boarding school is killed by her, a hunter named Sigurd is engaged to kill the monster.
| Writing | Amando de Ossorio | Screenplay |
| Production | Ricardo Muñoz Suay | Executive Producer |
| Sound | Antón García Abril | Original Music Composer |
| Production | José Antonio Pérez Giner | Producer |
| Directing | Amando de Ossorio | Director |
| Editing | Antonio Gimeno | Editor |
| Camera | Miguel Fernández Mila | Director of Photography |
| Editing | Mercedes Gimeno | Assistant Editor |
| Directing | Paulino González | Assistant Director |
| Art | Alfonso de Lucas | Set Designer |
| Camera | César Cruz | Still Photographer |
| Lighting | Julio Burgos | Assistant Electrician |
| Camera | Fernando Espiga | Camera Operator |
| Camera | Francisco Bermejo Miranda | Assistant Camera |
| Production | Julio Arribas | Production Assistant |
| Costume & Make-Up | José Luis Morales | Assistant Makeup Artist |
| Production | José Antonio Pérez Giner | Production Manager |
| Art | Cruz María Baleztena | Assistant Set Decoration |
| Sound | Tomás del Barrio | Sound Engineer |
| Directing | Gloria Roldán | Script Supervisor |
| Costume & Make-Up | Josefa Morales | Hairstylist |
| Crew | Alfredo Segoviano | Special Effects |
| Production | Ramón Escribano | Production Assistant |
| Costume & Make-Up | Dolores Merlo | Makeup Artist |
