Shredder tried to replace Bebop and Rocksteady with an "intelligent" and "thinking" Foot Soldier called "Alpha One." Because Bebop and Rocksteady were playing a videogame when Krang was programming Alpha One, the main computer malfunctioned and overloaded the device. As a result, Alpha One comes out more intelligent than Krang and Shredder wanted. Alpha One also gains the ability to control the other Foot robots.
Alpha One does not wish to work for what he considers inferior intellects like Krang and Shredder, so he sends them away in a lifepod. His plan is to transport all organic lifeforms on Earth to Dimension X, so he and his robots will have control of the Earth. Alpha One ended up being defeated by the turtles who turn his dimensional displacement device against him, transporting him to an unknown dimension.
Alpha One, after his artificial intelligence inceased, was the only Foot Soldier who could talk.