Follow the adventure of this fearless 11 year old boy, his genetically engineered super talking dog Dukey, and his 13-year old super genius scientist twin sisters, Susan and Mary who use Johnny as their guinea pig for their out-of-this-world scientific experiments. Johnny Test likes to live his extreme! From sports to video games, Johnny lives for excitement. With super genius sisters constantly testing out their latest experiments on him, there is never a dull moment in the life of Johnny Test.