Underfist: Halloween Bash (2008)

Underfist: Halloween Bash is an animated spinoff special of The Grim Adventures of Billy & Mandy. It aired on October 12, 2008.

Voices

 * Mandy/Aunt Sis/Kid/Ike - Grey DeLisle
 * Grim/Sperg/Giant Candy Bar - Greg Eagles
 * Billy/Harold/Pumpkin/Trick-or-Treater Eater#2 - Richard Horvitz
 * Irwin/Hoss's Mom - Vanessa Marshall
 * Hoss Delgado - Diedrich Bader
 * General Skarr/Candy Skeleton/Rat/Creepy Gnome - Armin Shimerman
 * Fred Fredburger - C.H. Greenblatt
 * Jeff the Spider - Maxwell Atoms
 * Dracula/Grandmama/Bougersnatch - Phil LaMarr
 * Mindy - Rachael MacFarlane
 * Bun-Bun/Trick-or-Treater Eater#1/Jimbo - Dave Wittenberg
 * Perkins/Peanutbutter Wheel/Tiny Skull - Greg Ellis
 * Confic/Humicun - Dan Gilvezan
 * Singer - Jess Harnell
 * Nergal/Police Officer/Tarvis - Martin Jarvis