A boy imagines a monster that helps him deal with his difficult life and see the world in a different way.
| Directing | J. A. Bayona | Director |
| Writing | Patrick Ness | Screenplay |
| Writing | Patrick Ness | Novel |
| Costume & Make-Up | Stephen Noble | Costume Design |
| Production | Belén Atienza | Producer |
| Camera | Óscar Faura | Director of Photography |
| Production | Bill Pohlad | Executive Producer |
| Editing | Jaume Martí | Editor |
| Production | Shaheen Baig | Casting |
| Production | Sandra Hermida | Executive Producer |
| Production | Enrique López Lavigne | Executive Producer |
| Production | Patrick Ness | Executive Producer |
| Production | Jeff Skoll | Executive Producer |
| Writing | Siobhan Dowd | Idea |
| Art | Ravi Bansal | Art Direction |
| Art | Jaime Anduiza | Art Direction |
| Production | Álvaro Augustin | Executive Producer |
| Production | Mitch Horwits | Executive Producer |
| Production | Patrick Wachsberger | Executive Producer |
| Art | Eugenio Caballero | Production Design |
| Sound | Fernando Velázquez | Original Music Composer |
| Editing | Bernat Vilaplana | Editor |
| Production | Jonathan King | Executive Producer |
| Production | Sandra Hermida | Co-Producer |
| Production | Sarah Wheale | Line Producer |
| Art | Dídac Bono | Art Direction |
| Art | Pilar Revuelta | Set Decoration |
| Production | Ghislain Barrois | Executive Producer |
| Crew | Tom Holland | Stand In |
| Crew | Steve Joberns | Thanks |
| Costume & Make-Up | Marese Langan | Hair Designer |
| Costume & Make-Up | Marese Langan | Makeup Designer |
| Crew | Montse Ribé | Makeup Effects |
| Sound | Oriol Tarragó | Sound Designer |
| Visual Effects | Félix Bergés | Visual Effects Supervisor |
| Visual Effects | Pau Costa | Special Effects Supervisor |
| Crew | David Martí | Makeup Effects |
| Art | Sean Sevestre | Concept Artist |
| Camera | Oriol Busquets | Camera Operator |
| Lighting | Víctor Sarasa | Electrician |
| Camera | Esther Mestres | Second Assistant "C" Camera |
| Crew | Anita Primett | Studio Teacher |
| Costume & Make-Up | Kelly Zampogna | Makeup Artist |
| Directing | Jan Zalar | Second Assistant Director |
| Camera | Javier González Leonardo | Key Grip |
| Camera | Guillem Huertas | First Assistant "A" Camera |
| Camera | Ramón Sánchez | Steadicam Operator |
| Lighting | Debora Witte | Electrician |
| Sound | Jose Ruiz | Foley Editor |
| Crew | Chus Lucas | Stunt Double |
| Visual Effects | Marcel Cifré | VFX Editor |
| Editing | Queralt González | Assistant Editor |
| Art | Jason Bond | Property Master |
| Crew | Jaume Martí | Post Production Supervisor |
| Art | Ariel Margolis | Property Master |
| Camera | Celine Gravez | Second Assistant Camera |
| Editing | Ana Charte | Assistant Editor |
| Sound | Jaime Gutiérrez Domínguez | Orchestrator |
| Directing | Glòria Blanes | Script Supervisor |
| Production | Maryllis Gonzalez | Production Accountant |
| Crew | Elizabeth Himelstein | Dialogue Coach |
| Crew | Sarah Shepherd | Dialect Coach |
| Production | Josué Corral | Assistant Production Manager |
| Directing | Eugenio Mira | Second Unit Director |
| Directing | Mónica Sánchez | Second Assistant Director |
| Sound | Don Hoffman | Sound Re-Recording Mixer |
| Sound | Kyle D. Krajewski | ADR Mixer |
| Crew | Ian van Temperley | Stunt Coordinator |
| Camera | Thomas Barrera | Camera Trainee |
| Production | Layla Merrick-Wolf | Casting Associate |
| Directing | Anna Capdevila | Third Assistant Director |
| Directing | Ruben Goldfarb | Second Assistant Director |
| Directing | Marc Rial | Second Assistant Director |
| Directing | Fernando Trullols | First Assistant Director |
| Art | Andrey Ryabovichev | Concept Artist |
| Art | Emma Saunders | Graphic Designer |
| Sound | Shaun Mills | Boom Operator |
| Camera | David Valldepérez | Camera Operator |
| Crew | Kieran O'Neal | Floor Runner |
| Art | Abner Marín | Sculptor |
| Sound | Marc Bech | Sound Effects Editor |
| Sound | Manuel Carrión | Foley Artist |
| Visual Effects | Wasselena Bilak | Visual Effects Coordinator |
| Visual Effects | Ainara Castro | Visual Effects Producer |
| Costume & Make-Up | Anna Aguilà | Costume Supervisor |
| Visual Effects | Geraint Hixson | Visual Effects Coordinator |
| Sound | Martí Albert | Sound Effects Editor |
| Sound | Albert Ribas | Dialogue Editor |
| Crew | Cuco Usín | Stunt Coordinator |
| Camera | Miquel Auguet | Second Assistant Camera |
| Production | Lyndsey Haluszczak | Assistant Production Coordinator |
| Visual Effects | Peter McDonald | Visual Effects Supervisor |
| Camera | Edward Botham | Second Assistant Camera |
| Camera | Albert Carreras | Camera Operator |
| Camera | Jordi Florensa | First Assistant Camera |
| Production | Carmen Romero | Extras Casting |
| Directing | Jesus Espin | Third Assistant Director |
| Art | Javier López Antía | Assistant Property Master |
| Sound | Marc Orts | Sound Re-Recording Mixer |
| Visual Effects | Alberto Bernad | VFX Editor |
| Production | Goyo Gámez | Unit Manager |
| Crew | Víctor Martí | Post Production Supervisor |
| Art | Marc Estrugo | Set Designer |
| Visual Effects | Srinivas Janapati | Visual Effects Coordinator |
| Crew | Paul Lowe | Stunt Double |
| Crew | Patricia Johnson | Unit Publicist |
| Crew | Cristina Malillos | Makeup Effects |
| Art | Joseph Díaz | Concept Artist |
| Crew | Tiger Rudge | Stunts |
| Camera | Yousef El Awage | Epk Camera Operator |
| Camera | José Haro | Still Photographer |
| Production | Margarita Huguet | Unit Production Manager |
| Art | Florian Müller | Set Designer |
| Art | Richard Rowntree | Greensman |
| Sound | Laura Díez Mora | Dialogue Editor |
| Lighting | José Luis Rodríguez | Gaffer |
| Camera | Quim Vives | Still Photographer |
| Production | Inés Font | Post Production Coordinator |
| Production | Jen Rooks | Production Coordinator |
| Visual Effects | Ferran Domenech | Visual Effects Supervisor |
