Rosh O'Monster

Gregg Berger

The Gromble (voice)

Charlie Adler

Ickis (voice)

Christine Cavanaugh

Oblina (voice)

Jim Belushi

Simon the Monster Hunter (voice)

Kath Soucie

Blorp 2+4 / Woman (voice)

Lacey Chabert

Girl (voice)

Michael Dorn

Borl / Chauffer (voice)

Bronson Pinchot

Deitrich Dunlap (voice)

David Eccles

Krumm (voice) / Snorch (voice)

Tim Curry

Zimbo (voice)

Shelley Duvall

Ocka (voice)

Beverly Archer

The Library Monster (voice)

Edward Winter

Dr. Buzz Kutt (voice)

Billy Vera

Slickis (voice)

Marcia Strassman

Harryette (voice)

Bill Fagerbakke

Carl (voice)