 | George MacKay als Jack Marrowbone |
 | Anya Taylor-Joy als Allie |
 | Charlie Heaton als Billy Marrowbone |
 | Mia Goth als Jane Marrowbone |
 | Matthew Stagg als Sam Marrowbone |
 | Nicola Harrison als Rose Marrowbone, Mother |
 | Kyle Soller als Tom Porter |
 | Tom Fisher als Simon Fairbairn, Father |
 | Myra Kathryn Pearse als Molly |
 | Paul Jesson als Doctor |
 | Robert Strange als Monster |
| Laura Brook als Thelma (uncredited) |
 | Adam Quintero als Mr. Gouldman (voice) (uncredited) |
| Sergio G. Sánchez | Writer |
| Sergio G. Sánchez | Director |
| Fernando Velázquez | Music |
| Oriol Tarragó | Supervising Sound Editor |
| Oriol Tarragó | Sound Designer |
| Belén Atienza | Producer |
| Sonia Grande | Costume Design |
| Marc Orts | Sound Re-Recording Mixer |
| Xavi Giménez | Director of Photography |
| Wanda Morales | Assistant Costume Designer |
| Lucas Fernández | Boom Operator |
| Cristina Sánchez Belmonte | Script Supervisor |
| Jaime Anduiza | Art Direction |
| Marta Monistrol | Foley |
| Sergi Bartrolí | Second Unit Director of Photography |
| Denise Kum | Prosthetic Designer |
| Álvaro Augustin | Producer |
| Patrick Salvador | Production Design |
| Emily Jacobs | Casting Associate |
| Glòria Blanes | Script Supervisor |
| Marc Gonell | Foley |
| Ghislain Barrois | Producer |
| Pelayo Gutiérrez | Sound Designer |
| Pelayo Gutiérrez | Supervising Sound Editor |
| Elena Ruiz | Editor |
| Karen Lindsay-Stewart | Casting |
| Tamara Arévalo | Boom Operator |
| Nacho Martinez | Electrician |
| Andrea Paralta | Dialogue Editor |
| Chisko Blanco | Electrician |
| Beatriz Delgado | First Assistant Camera |
| Enric Masip | Special Effects Supervisor |
| Francesc Carreras | First Assistant Camera |
| Ana Cuerda | Assistant Costume Designer |
| Boi Martínez | Foley Editor |
| Sara Cabrera | Set Costumer |
| Ana Charte | First Assistant Editor |
| Edu Canet | Camera Operator |
| Quim Vives | Still Photographer |
| Àlex Villagrasa | Visual Effects Supervisor |
| Sergio Burmann | Sound Mixer |
| Kike Maíllo | Second Unit Director |
| Nuria Mbomio | Makeup & Hair |
| Grace McComisky | Prosthetic Makeup Artist |
| Chris Fitzpatrick | Prosthetic Supervisor |
| Sandra Hermida | Production Manager |
| Margarita Huguet | Unit Production Manager |
| F. Javier Soto | First Assistant Director |
| Olga Pujalte López | Second Assistant Director |
| Pep Parés Font | Third Assistant Director |
| Edu Glez | Graphic Designer |
| Roberto Álvarez Espinedo | Property Master |
| Marc Carreres | Visual Effects Editor |
| Dan Adams | Utility Stunts |
| Roberto Bonacini | Stunts |
| César Solar | Stunt Coordinator |
| Cuco Usín | Stunt Coordinator |
| Javier González Leonardo | Key Grip |
| Celine Gravez | Second Assistant Camera |
| Martí Maluquer | Gaffer |
| Almudena Cormenzana | Production Coordinator |
| J. A. Bayona | Executive Producer |
