According to Streaky, sometime between the time banishment of Zod and his followers and the explosion of Krypton (when Krypto and Kal-El were babes), the Science Council had a problem: Zod's "Three Naughty Doggies", Vlea, Tronk, and Dom. All three of them acted violent and impossible to control. The council let Jor-El handle them, and he did: sending them to their own kind on a planet near Sirius, the dog star, via spaceship. But when they were luanch into space, the dogs attack the controls, causing them into hypersleep and be off course.
Years later, they crash land and awake on earth, near Metropolis no less; taking quick notice and control of their powers. With their new found powers to enable them to fullfil their ambitions, the three head to local carnival, where Streaky was too, enjoying the food until the evil trio show up and cause trouble. The Cat of Steel tries to keep things under-control, but finds himself overwhelmed by the 3. He then flies to Tahiti, where Krypto was with his family on vacation, with the 3 bad Kryptonian dogs following close behind.
With the the 5 super pets in the same area, Kevin convince the rest of the family to go into their cabin on the beach for their safety as well as protecting Krypto's identity.
The battle between the Cat and Dog of Steel against Zod's 3 Naughty Doggies was intense, making an illusion that an intense storm was occurring. But when Dom saw his side was failing, he quickly grab Kevin, who checking to see if the arose of clear, and gave Krypto and Streaky an ultimatum: Make him ruler of earth or he'll kill Kevin, and with little choice, Krypto chose the former. But in order to make the transfer of power "official" he needed to get some things from the Fortress of Solitude.
After getting all three of Zod's dogs together, Krypto was going to crown them rulers of earth, but it turn out to be a trick, as Krypto carried Kryptonite in a lead box. After exposing the 3 to the point of passing out, Krypto and Streaky take them back to their ship, which they managed to fix thanks to a help-program of Jor-el, and send them back to original destination.