Shredder commanded the Foot from Japan until he learned that Yoshi was training his own ninjas in New York City, and moved his inner clan there with the objective of finding and killing Yoshi and his students. However, Shredder, Karai (a renamed Miwa), Dogpound, Fishface, and their reluctant new conscript, former TCRI inventor Baxter Stockman, fail time and again to do so. Karai learned of the Kraang, an alien race responsible for the mutations of Splinter and the Turtles, who are secretly plotting to conquer and terraform Earth, but Shredder dismisses them until he captures one himself and learns from it that the Turtles guard April O'Neil, whose half-Kraang genetics were need for their invasion. After another failed attempt to kill the Turtles, Shredder allies the Foot Clan with the Kraang, as they share a mutual enemy in the Hamato Clan.