When the Boogey Man causes Grim to lose his powers, rank, and title in the Underworld Court for misusing his powers, he plots to seek out Horror's Hand and take over the world. It's up to Billy, Mandy, Irwin, and Grim to get to Horror's Hand before the Boogey Man does.
Unfortunately the movie Billy & Mandy's Big Boogey Adventure is not yet available on HBO Max.
| Directing | Robert Alvarez | Director |
| Directing | Russell Calabrese | Director |
| Directing | Shaun Cashman | Director |
| Directing | Phil Cummings | Director |
| Directing | Matt Engstrom | Director |
| Directing | Eddy Houchins | Director |
| Directing | Gordon Kent | Director |
| Directing | Christine Kolosov | Director |
| Directing | Michel Lyman | Director |
| Directing | Sue Perrotto | Director |
| Directing | Kris Sherwood | Director |
| Visual Effects | Joo-Shik Yoo | Animation Director |
| Visual Effects | Soo-hyun Park | Animation Director |
| Visual Effects | Kwang-bae Park | Animation Director |
| Visual Effects | Hyung-tae Kim | Animation Director |
| Visual Effects | Lee Jae Bok | Animation Director |
| Production | Shaun Cashman | Producer |
| Production | Louis J. Cuck | Producer |
| Production | Jennifer Pelphrey | Producer |
| Production | Brian A. Miller | Executive Producer |
| Editing | Illya Owens | Editor |
| Production | Kris Zimmerman | Casting |
| Art | Marc Perry | Art Direction |
| Production | Jay Bastian | Executive In Charge Of Production |
| Production | James Silverman | Production Manager |
| Crew | Tony Tedford | Post Production Supervisor |
| Crew | Mark Bachand | Prop Maker |
| Crew | Anna Chambers | Prop Maker |
| Sound | Jesse Arruda | Sound Editor |
| Sound | Brad Brock | Sound Re-Recording Mixer |
| Sound | Timothy J. Garrity | Sound Re-Recording Mixer |
| Editing | Jim Hearn | Dialogue Editor |
| Sound | Glenn Oyabe | Sound Editor |
| Sound | Eric Sequeira | Sound Re-Recording Mixer |
| Sound | Robert Serda | Sound Engineer |
| Visual Effects | Azariah Owens | Visual Effects |
| Visual Effects | Sandy Benenati | Animation |
| Writing | Joe Binggeli | Characters |
| Writing | Frank Homiski | Characters |
| Visual Effects | Phil Rynda | Color Designer |
| Art | Cliff Voorhees | Background Designer |
| Art | Don Watson | Background Designer |
| Writing | Eva Wu | Characters |
| Editing | Rob Desales | Editor |
| Crew | Alicia Parkinson | Post Production Supervisor |
| Crew | Antonio Gonella | Supervising Technical Director |
| Production | Ben Pile | Producer |
| Production | Pietro Piumetti | Producer |
| Production | Shalonda Ware | Production Accountant |
| Writing | Marc Perry | Characters |
| Writing | Maxwell Atoms | Story |
| Writing | Maxwell Atoms | Writer |
| Writing | Nina G. Bargiel | Writer |
| Writing | Jeremy J. Bargiel | Writer |
| Art | Jay Baker | Storyboard Artist |
| Art | Tara Whitaker | Storyboard Artist |
| Art | Spencer Laudiero | Storyboard Artist |
| Art | Shaun Cashman | Storyboard Artist |
| Art | Mike Diederich | Storyboard Artist |
| Art | Maxwell Atoms | Storyboard Artist |
| Art | John Holmquist | Storyboard Artist |
| Art | Ian Wasseluk | Storyboard Artist |
| Art | Chris Mitchell | Storyboard Artist |
| Art | Chris Headrick | Storyboard Artist |
| Art | C.H. Greenblatt | Storyboard Artist |
| Art | Alex Almaguer | Storyboard Artist |
| Writing | Maxwell Atoms | Characters |
| Production | Maxwell Atoms | Executive Producer |
| Art | Bill Flores | Background Designer |
| Sound | Drew Neumann | Original Music Composer |
| Sound | Gregory Hinde | Original Music Composer |
| Sound | Kris Zimmerman | Sound Director |
| Art | Joe Binggeli | Background Designer |
| Directing | Juli Murphy | Director |
| Writing | Phil Rynda | Characters |
