Grey DeLisle

as Mandy (voice)

Ben Diskin

as Numbuh 1 / Numbuh 2 / Delightful Children F.D.T.L. (voice)

Lauren Tom

as Numbuh 3 (voice)

Dee Bradley Baker

as Numbuh 4 / Delightful Children F.D.T.L. (voice)

Cree Summer

as Numbuh 5 / Delightful Children F.D.T.L. (voice)

Richard Steven Horvitz

as Billy / Harold (voice)

Greg Eagles

as Grim (voice)

Rachael MacFarlane

as Numbuh 362 (voice)

Matt Levin

as Numbuh 60 (voice)

Tony Sampson

as Eddy (voice)

C.H. Greenblatt

as Fred Fredburger (voice)

Rachael MacFarlane

as Mindy / Numbuh 362 (voice)

Vanessa Marshall

as Irwin (voice)

Dave Wittenberg

as Numbuh 74.239 (voice)

Matt Hill

as Ed (voice) (uncredited)

Sam Vincent

as Edd (voice) (uncredited)