High Quality Content by WIKIPEDIA articles! This is a list of Johnny Test characters from the animated television series Johnny Test. The show is a Canadian/American animated television series. It premiered on Kids` WB, a division of The WB Television Network, on September 17, 2005. Five months later, it was introduced to Cartoon Network UK on January 12, 2006. The series revolves around the adventures of Johnny Test, an 11-year-old suburban boy who lives with his super-genius, 13-year-old twin sisters, Susan and Mary, in the Test residence of the fictional town of Porkbelly.