The series revolves around the adventures of the titular character, Johnny Test, an 11-year-old suburban boy who lives with his parents, his "super-genius" 13-year-old twin sisters, Susan and Mary, who are scientists and best friends with each other, and a talking dog named Dukey. They reside in the fictional town of Porkbelly in North America. Johnny is often used as a test subject for his genius twin sisters' inventions and experiments, ranging from gadgets to superpowers. Their experiments often cause problems that he must resolve, and he must sometimes fight villains in the process. He occasionally saves the world with his sisters' inventions. The series was created by Scott Fellows, a writer for the Fairly OddParents, and creator of Ned's Declassified School Survival Guide. The first season was produced by Warner Bros. Animation under Chris Savino. Savino was well known as showrunner for the last two seasons of Dexter's Laboratory and the Powerpuff Girls. The show suffered budget cuts after season one due to the merger between the WB and UPN into the CW, and production would later be taken over by Cookie Jar Entertainment, and later by DHX Media (now WildBrain). The series was met with a revival on Netflix in 2021.