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