Young Johnny is gung-ho and full of courage. Johnny's brainiac twin sisters, Susan and Mary, use Johnny as their guinea pig for their outrageous scientific experiments. If they can dream it up, Johnny will do it; as long as his genetically engineered super dog, Dukey, can come along.
James Arnold Taylor
Johnny Test (voice)
Maryke Hendrikse
Susan Test (voice)
Ashleigh Ball
Mary Test (voice)
Lee Tockar
The General / Bling-Bling Boy (voice)
Ian James Corlett
Hugh Test (voice)
Trevor Devall
Dukey (voice)
Kathleen Barr
Lila Test (voice)
Scott McNeil
Mr. White / Bumper (voice)
Bill Mondy
Mr. Black (voice)
Johnny Test
Dexter's Laboratory
My Life as a Teenage Robot
The Adventures of Jimmy Neutron: Boy Genius
Cloudy with a Chance of Meatballs
Harvey Beaks
Chip 'n' Dale Rescue Rangers
CatDog
DuckTales
The Ren & Stimpy Show
Animaniacs
T.U.F.F. Puppy