Brian Froud

as Jules Peeters

as Frank

as ICU Doctor (1 episode)

as Lou (26 episodes)

as Leon (voice)

as Robert

as Antonio (78 episodes)

as (voice) (1 episode)

as Marty (voice) (40 episodes)

as Nature Doc Narrator (voice)

as Sam (voice) (13 episodes)

as Sam (13 episodes)

as Additional Voices (52 episodes), as Gray Goblin (1 episode)

as Harold (voice)

as Beezy (voice) (104 episodes)

as Harold (voice) (27 episodes)

as Harold (voice) (27 episodes)