Professor Willard W. Willard, one of Donatello's heroes, invents a Molecular Intensifier to control the growth of living things. Krang hears about it and sends Shredder to retrieve it. While testing the Intensifier, the Professor accidentally zaps his pet monkey, Jocko who grows to 30 feet in height. He also zaps some roots which then grown enormously and begin to take over the city, turning it into a jungle.