A newly developed large Centipede type Badnik designed for use in desert areas. You never know when they will suddenly emerge from quicksand, and be mindful of its robust body that is resistant to attacks. — Sonic The Hedgehog 4: Episode II Website
Its appearance is similar to a large centipede. It attacks by jumping out of the sand in the Oil Desert Zone. It has the same name as a previous robot and a similar color scheme to another. Sandworms also have a more violent-looking appearance.
Sandworm is the only badnik that appears in Sonic the Hedgehog 4: Episode II to be an entirely different Badnik with the same name as a previous one.
Sandworm is the only Badnik in Sonic the Hedgehog 4: Episode II that is resistant to every type of attack. Therefore, it is impossible to tell if it contains an animal.