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.
| Visual Effects | Joo-Shik Yoo | Animation Director |
| Visual Effects | Soo-hyun Park | Animation Director |
| Directing | Robert Alvarez | Director |
| Production | Shaun Cashman | Producer |
| Editing | Jim Hearn | Dialogue Editor |
| Production | Shalonda Ware | Production Accountant |
| Crew | Anna Chambers | Prop Maker |
| Sound | Brad Brock | Sound Re-Recording Mixer |
| Directing | Russell Calabrese | Director |
| Directing | Gordon Kent | Director |
| Directing | Christine Kolosov | Director |
| Directing | Michel Lyman | Director |
| Visual Effects | Phil Rynda | Color Designer |
| Editing | Rob Desales | Editor |
| Directing | Matt Engstrom | Director |
| Visual Effects | Hyung-tae Kim | Animation Director |
| Visual Effects | Lee Jae Bok | Animation Director |
| Production | Louis J. Cuck | Producer |
| Production | Kris Zimmerman | Casting |
| Production | Jay Bastian | Executive In Charge Of Production |
| Directing | Phil Cummings | Director |
| Editing | Illya Owens | Editor |
| Writing | Frank Homiski | Characters |
| Production | Jennifer Pelphrey | Producer |
| Art | Marc Perry | Art Direction |
| Production | Brian A. Miller | Executive Producer |
| Visual Effects | Sandy Benenati | Animation |
| Crew | Antonio Gonella | Supervising Technical Director |
| Crew | Tony Tedford | Post Production Supervisor |
| Directing | Sue Perrotto | Director |
| Directing | Kris Sherwood | Director |
| Visual Effects | Kwang-bae Park | Animation Director |
| Crew | Mark Bachand | Prop Maker |
| Sound | Timothy J. Garrity | Sound Re-Recording Mixer |
| Writing | Eva Wu | Characters |
| Art | Don Watson | Background Designer |
| Directing | Shaun Cashman | Director |
| Sound | Jesse Aruda | Sound Editor |
| Visual Effects | Azariah Owens | Visual Effects |
| Art | Cliff Voorhees | Background Designer |
| Writing | Marc Perry | Characters |
| Sound | Eric Sequeira | Sound Re-Recording Mixer |
| Crew | Alicia Parkinson | Post Production Supervisor |
| Production | Pietro Piumetti | Producer |
| Sound | Glenn Oyabe | Sound Editor |
| Writing | Joe Binggeli | Characters |
| Production | Ben Pile | Producer |
| Directing | Eddy Houchins | Director |
| Production | James Silverman | Production Manager |
| Sound | Robert Serda | Sound Engineer |
| Writing | Jeremy J. Bargiel | Writer |
| Writing | Nina G. Bargiel | Writer |
| Writing | Maxwell Atoms | Writer |
| Writing | Maxwell Atoms | Story |
| Art | Tara Whitaker | Storyboard Artist |
| Art | Maxwell Atoms | Storyboard Artist |
| Art | John Holmquist | Storyboard Artist |
| Art | Chris Headrick | Storyboard Artist |
| Art | C.H. Greenblatt | Storyboard Artist |
| Art | Chris Mitchell | Storyboard Artist |
| Art | Alex Almaguer | Storyboard Artist |
| Art | Jay Baker | Storyboard Artist |
| Art | Spencer Laudiero | Storyboard Artist |
| Art | Shaun Cashman | Storyboard Artist |
| Art | Ian Wasseluk | Storyboard Artist |
| Art | Mike Diederich | 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 |
| Directing | Juli Murphy | Director |
| Art | Joe Binggeli | Background Designer |
| Writing | Phil Rynda | Characters |
