Based on the award-winning comic book by Mike Mignola (creator of Hellboy), The Amazing Screw-On Head chronicles the adventures of a Civil War-era secret agent with an extraordinary special power who serves under president Abraham Lincoln.
| Actor | Role |
|---|---|
 Paul GiamattiScrew-On Head (voice) | Screw-On Head (voice) |
 David Hyde PierceEmperor Zombie (voice) | Emperor Zombie (voice) |
 Patton OswaltMr. Groin (voice) | Mr. Groin (voice) |
 Corey BurtonPresident Abraham Lincoln / Demon / Professor Faust (voice) | President Abraham Lincoln / Demon / Professor Faust (voice) |
 Mindy SterlingAggie / Geraldine (voice) | Aggie / Geraldine (voice) |
 Molly ShannonPatience the Vampire (voice) | Patience the Vampire (voice) |