The Sigma Force first encounter Goku, Pan, and Trunks when they are exploring Planet M-2. They capture Goku and Trunks, but leave Pan behind. Later when Pan enters Rilldo's base, Natt is deployed to take care off her, but he is destroyed. Later when Goku fights them, the rest of the Sigma Force combine into the powerful Sigma Force Cannon.
- The Sigma Force are slightly similar to the Ginyu Force. They are an organized team of fighters and they both pose before fighting, though the Sigma Force does it less.