This is a list of the many characters from the animated television series Johnny Test. Jonathan "Johnny" Test voiced by James Arnold Taylor : A troublesome, unpredictable, and widely iconic year-old boy who is the brother of Susan and Mary and the son of Hugh and Lila. He is the main protagonist of the show. He is often called the "kid with the flaming hair" due to having scarlet red highlights in his yellow hair. He is most often seen wearing green cargo pants and a black shirt with a trefoil symbol on it, which he wears under a navy blue dress shirt, a watch that he rarely uses and black hi-tops.
Top definition. Johnny Test unknown. Teletoon's shitty rip-off of Dexter's Lab. Some kid from Cartoon Network with flaming hair that has a talking dog, keeps breaking in to their sister's lab and always yells. Me: Stop yelling. A show with an 11 year old boy with a "flaming hair", with a red-haired 15 year old twin genius sisters with a streak and attitude of an hoe, and their main purpose on the show is to drool over a weird fucking guido.