In the world of the Murkworks where nightmares are made, the evil Synonamess Botch hatches a scheme to make non-stop nightmares. Only Ralph and Mumford, misfits from the cheery land of Frivoli where good dreams are made, can stop him.
Unfortunately the movie Twice Upon a Time is not yet available on HBO Max.
| Directing | John Korty | Director |
| Directing | Charles Swenson | Director |
| Writing | Bill Couturié | Screenplay |
| Writing | Suella Kennedy | Story |
| Writing | John Korty | Story |
| Writing | Charles Swenson | Writer |
| Editing | Jennifer Gallagher | Editor |
| Writing | Suella Kennedy | Screenplay |
| Writing | Bill Couturié | Story |
| Writing | John Korty | Screenplay |
| Production | Suella Kennedy | Associate Producer |
| Production | Barbara Wright | Associate Producer |
| Sound | Dawn Atkinson | Original Music Composer |
| Sound | Ken Melville | Original Music Composer |
| Sound | Michael McDonald | Songs |
| Production | Kathryn Witte | Production Manager |
| Sound | John Benson | Supervising Sound Editor |
| Sound | Ken Fischer | Sound Effects Editor |
| Sound | Dan Gleich | Additional Sound Re-Recordist |
| Sound | Luther Greene | Sound Re-Recording Mixer |
| Sound | Walt Kraemer | Sound Designer |
| Sound | Barbara McBane | Dialogue Editor |
| Sound | Michael Minkler | Sound Re-Recording Mixer |
| Sound | Catherine Ryan | Sound Effects Editor |
| Sound | Karen Spangenberg | Assistant Dialogue Editor |
| Sound | Dale Strumpell | Sound Re-Recording Mixer |
| Sound | Dennie Thorpe | Foley Artist |
| Sound | Karen G. Wilson | Sound Effects Editor |
| Sound | Barbara McBane | Sound Editor |
| Crew | David Fincher | Special Effects |
| Visual Effects | Chris R. Green | Animation |
| Camera | John Baker | Still Photographer |
| Camera | Peter Crosman | Still Photographer |
| Visual Effects | John Baker | Animation Technical Director |
| Camera | Paul Marbury | Assistant Camera |
| Camera | Peter Thomas | Key Grip |
| Visual Effects | John Allan Armstrong | Animation |
| Visual Effects | Peter Crosman | Animation |
| Visual Effects | George Evelyn | Animation |
| Visual Effects | Chuck Eyler | Animation |
| Visual Effects | Nick Hale | Animation |
| Visual Effects | Randy Hamm | Animation |
| Visual Effects | Doug Haynes | Animation |
| Visual Effects | Bruce Heller | Animation |
| Visual Effects | Harley Jessup | Character Designer |
| Visual Effects | Brad Jones | Animation |
| Visual Effects | John Korty | Character Designer |
| Visual Effects | Carol Millican | Animation |
| Visual Effects | Nancy Morita | Animation |
| Visual Effects | Kris Moser | Animation |
| Visual Effects | Brian Narelle | Animation Supervisor |
| Visual Effects | Will Noble | Animation |
| Visual Effects | David Pettigrew | Animation |
| Visual Effects | Kaj Pindal | Animation |
| Visual Effects | Deborah Short | Animation |
| Visual Effects | John T. Van Vliet | Animation |
| Visual Effects | Mark West | Animation |
| Visual Effects | Peggy Yamamoto | Animation |
| Costume & Make-Up | Sue Miller | Wardrobe Coordinator |
| Editing | Sandina Bailo-Lape | Assistant Editor |
| Editing | Donah Bassett | Negative Cutter |
| Editing | Ronald Jacobs | Assistant Editor |
| Editing | Nancy Jencks | Assistant Editor |
| Editing | Kathleen Korth | Assistant Editor |
| Editing | Mary Helen Leasman | Assistant Editor |
| Editing | Emily Craig Macrae | Assistant Editor |
| Editing | Patrick McHugh | Assistant Editor |
| Editing | Karen Spangenberg | Assistant Editor |
| Editing | Julie Stept | Assistant Editor |
| Sound | Susan R. Crutcher | Music Editor |
| Sound | Vivien Hillgrove Gilliam | Music Editor |
| Sound | Edie Lehmann Boddicker | Vocals |
| Directing | Suella Kennedy | Script Supervisor |
| Production | Bill Couturié | Producer |
| Production | George Lucas | Executive Producer |
| Art | Harley Jessup | Art Direction |
