A serpent, created by radioactivity, threatens a Spanish coastal town.
| Directing | Amando de Ossorio | Director |
| Editing | José Antonio Rojo | Editor |
| Sound | Manel Santisteban | Original Music Composer |
| Writing | Amando de Ossorio | Screenplay |
| Camera | Raúl Pérez Cubero | Director of Photography |
| Production | José Frade | Producer |
| Camera | Antonio Sáiz Palazón | Camera Operator |
| Art | Vincent D. White | Construction Coordinator |
| Crew | Joseph Vargas | Special Effects |
| Costume & Make-Up | Fernando Florido | Makeup Artist |
| Crew | Thomas Urbant | Special Effects |
| Costume & Make-Up | Dolores García Rey | Hairstylist |
| Crew | Frank Cuttlet | Special Effects |
| Camera | Alex Digest | Still Photographer |
| Directing | Erika Szel | Script Supervisor |
| Art | José Luis Galicia | Art Direction |
| Sound | Joseph Cherry | Sound Recordist |
| Camera | Salvador Gómez Calle | Assistant Camera |
