Underwater deep-sea miners encounter a Soviet wreck and bring back a dangerous cargo to their base on the ocean floor with horrifying results. The crew of the mining base must fight to survive against a genetic mutation that hunts them down one by one.
Unfortunately the movie Leviathan is not yet available on HBO Max.
| Directing | George P. Cosmatos | Director |
| Visual Effects | Jon Curtis Price | Creature Design |
| Writing | David Webb Peoples | Story |
| Writing | David Webb Peoples | Screenplay |
| Writing | Jeb Stuart | Screenplay |
| Production | Aurelio De Laurentiis | Producer |
| Production | Luigi De Laurentiis | Producer |
| Production | Charles Gordon | Executive Producer |
| Production | Lawrence Gordon | Executive Producer |
| Sound | Jerry Goldsmith | Original Music Composer |
| Camera | Alex Thomson | Director of Photography |
| Editing | John F. Burnett | Editor |
| Editing | Roberto Silvi | Editor |
| Sound | Nancy Beach | Orchestrator |
| Sound | Jerry Goldsmith | Conductor |
| Sound | Kenneth Hall | Supervising Music Editor |
| Sound | Arthur Morton | Orchestrator |
| Sound | Michael Dittrick | Music Editor |
| Editing | Gillian L. Hutshing | Assistant Editor |
| Editing | Richard Leeman | First Assistant Editor |
| Editing | Aldo Manni | Negative Cutter |
| Costume & Make-Up | Yvonne Zarb Cousin | Costumer |
| Camera | Ramón Bravo | Underwater Camera |
| Camera | Phil Barthropp | Underwater Camera |
| Camera | Ernesto Natoli | Assistant Camera |
| Lighting | Fabio Scepi | Electrician |
| Camera | Mike Valentine | Underwater Camera |
| Costume & Make-Up | Bruce Barlow | Special Effects Makeup Artist |
| Costume & Make-Up | Katalin Elek | Makeup Artist |
| Costume & Make-Up | Zoltan Elek | Key Makeup Artist |
| Costume & Make-Up | Marina Marin | Assistant Hairstylist |
| Costume & Make-Up | John Rosengrant | Special Effects Makeup Artist |
| Costume & Make-Up | Aldo Signoretti | Key Hair Stylist |
| Directing | Marco Alberti | Second Second Assistant Director |
| Directing | Matt Earl Beesley | First Assistant Director |
| Directing | Luca Lachin | Second Assistant Director |
| Directing | Kuki López Rodero | First Assistant Director |
| Directing | David Turchi | Second Assistant Director |
| Production | Jane Feinberg | Casting |
| Production | Mike Fenton | Casting |
| Production | Lynda Gordon | Casting |
| Art | Ron Cobb | Production Design |
| Art | Franco Ceraolo | Art Direction |
| Art | Pier Luigi Basile | Supervising Art Director |
| Art | David F. Klassen | Art Direction |
| Art | William Ladd Skinner | Supervising Art Director |
| Art | Bruno Cesari | Set Decoration |
| Art | Robert Gould | Set Decoration |
| Costume & Make-Up | April Ferry | Costume Design |
| Crew | Giorgio De Vincenzo | Post Production Supervisor |
| Production | Lucio Trentini | Production Supervisor |
| Art | Maria Teresa Barbasso | Set Designer |
| Production | Roberto Malerba | Location Manager |
| Directing | Ceri Evans | Script Supervisor |
| Production | Gabriella Toro | Production Coordinator |
| Sound | Robin Gregory | Sound Mixer |
| Visual Effects | Stan Winston | Creature Effects Technical Director |
| Production | Maurizio Amati | Executive In Charge Of Production |
| Visual Effects | Alec Gillis | Creature Design |
| Visual Effects | Richard J. Landon | Creature Design |
| Visual Effects | Shane Mahan | Creature Design |
| Visual Effects | Shannon Shea | Creature Design |
| Visual Effects | John Rosengrant | Creature Design |
| Visual Effects | Tom Woodruff Jr. | Creature Design |
| Visual Effects | Nick Allder | Effects Supervisor |
| Visual Effects | Barry Nolan | Visual Effects Supervisor |
| Camera | Giuseppe Maccari | Additional Photography |
| Production | Paolo Gargano | Unit Manager |
| Production | Giovanna Di Michele | Production Accountant |
| Camera | Nic Milner | First Assistant Camera |
| Camera | Chyna Thomson | Second Assistant Camera |
| Sound | Terry Sharratt | Boom Operator |
| Art | Alfredo Vincenti | Construction Coordinator |
| Art | Craig Edgar | Set Designer |
| Art | William James Teegarden | Set Designer |
| Art | Alessandro Alberti | Set Designer |
| Art | Daniela Giovannoni | Set Designer |
| Art | Susanna Giovannini | Assistant Set Designer |
| Art | Marco Trentini | Assistant Set Designer |
| Art | Steve Burg | Concept Artist |
| Art | David J. Negron Sr. | Storyboard Artist |
| Art | Fred Lucky | Storyboard Artist |
| Art | David J. Negrón Jr. | Production Illustrator |
| Art | Etta Leff | Assistant Set Decoration |
| Art | Cynthia Sleiter | Assistant Set Decoration |
| Art | Alfio Tempera | Set Buyer |
| Costume & Make-Up | Carla Latini | Wardrobe Supervisor |
| Costume & Make-Up | Giampiero Grassi | Dresser |
| Costume & Make-Up | Augusto Grassi | Dresser |
| Art | Boni Fraulo | Property Master |
| Art | Paolo Luciani | Assistant Property Master |
| Art | Giuseppe Cancellara | Assistant Property Master |
| Art | Domenico Mancino | Assistant Property Master |
| Art | Ivano Tedeschi | Painter |
| Art | Agostino Bivi | Painter |
| Lighting | Roy Larner | Gaffer |
| Lighting | Fernando Massaccesi | Gaffer |
| Camera | Tony Cridlin | Key Grip |
| Camera | Ennio Brizzolari | Key Grip |
| Crew | Marco Carosi | Playback Coordinator |
| Production | Daniela Vecchi | Assistant Production Coordinator |
| Production | Luigi Scardino | Assistant Accountant |
| Production | Otello Tomassini | Assistant Accountant |
| Crew | Randell Dennis Widner | Stunt Coordinator |
| Crew | Rocco Lerro | Stunt Coordinator |
| Crew | Ottaviano Dell'Acqua | Stunts |
| Crew | Fabiola Tocca | Stunts |
| Crew | Alessandro Ponti | Stunts |
| Crew | Charles Tabansi | Stunts |
| Crew | Massimo Giovannucci | Stunts |
| Crew | Bobby Rhodes | Stunts |
| Crew | Paola Giacomini | Stunts |
| Crew | Giovanni Corridori | Special Effects Coordinator |
| Crew | Alan Bryce | Special Effects |
| Crew | John Hatt | Special Effects |
| Crew | Renato Agostini | Special Effects |
| Editing | Beverly Pinnas | Assistant Editor |
| Editing | Giorgio Conti | Assistant Editor |
| Editing | Roberto Olivieri | Assistant Editor |
| Sound | Mike Le Mare | Supervising Sound Editor |
| Sound | Terry Porter | Sound Re-Recording Mixer |
| Sound | Mel Metcalfe | Sound Re-Recording Mixer |
| Sound | David J. Hudson | Sound Re-Recording Mixer |
| Sound | David Lewis Yewdall | Sound Effects Editor |
| Sound | Karola Storr | Foley Editor |
| Sound | Virginia Cook-McGowan | Dialogue Editor |
| Sound | Teri E. Dorman | Dialogue Editor |
| Sound | John Post | Foley Artist |
| Sound | James Dean Fisher | Foley Artist |
| Sound | Jay Engel | ADR Editor |
| Sound | Steve Schwalbe | Assistant Sound Editor |
| Sound | Desmond Cannon | Assistant Sound Editor |
| Sound | Janelle Showalter | Assistant Sound Editor |
| Sound | Laura Graham | Assistant Sound Editor |
| Sound | Carmen Hocson Baker | Assistant Sound Editor |
| Crew | Alan Snelling | Score Engineer |
| Art | Richard Malzahn | Graphic Designer |
| Visual Effects | Charles L. Finance | Visual Effects Production Manager |
| Visual Effects | Robert Habros | Visual Effects Camera |
| Visual Effects | David S. Williams Jr. | Visual Effects Camera |
| Visual Effects | David B. Sharp | Modelling Supervisor |
| Visual Effects | James Belohovek | Modeling |
| Visual Effects | C. Mitchell Bryan | Modeling |
| Visual Effects | Eric Skipper | Modeling |
| Art | Alvaro Belsole | Construction Coordinator |
| Production | Franca Tasso | Production Coordinator |
| Directing | Francesca Ghiotto | Script Supervisor |
| Camera | Federico Del Zoppo | "B" Camera Operator |
| Camera | Gaby Bzdega | Assistant Camera |
| Camera | Sergio Strizzi | Still Photographer |
| Camera | Francesco Bellomo | Still Photographer |
| Camera | David James | Still Photographer |
| Editing | Carlo La Bella | Colorist |
