Field commander and second-in-command

While in the Army and working as an operative, Conrad Hauser was best friends with Rex Lewis and engaged to Ana Lewis. After Rex was presumed killed during an attack, Conrad abandoned Ana over grief at failing to save her brother.

He was in charge of a convoy delivering weapons to the United Nations when it was attacked, and during the attack recognized the Baroness as his former fiancee Ana. Using his knowledge he blackmailed his way onto the GI Joe team. Hauser goes under the code name of Duke.

After being captured in Paris, Duke is interrogated by M.A.R.S Industries owner, James McCullen. Duke learns the awful truth of what really happened to Rex Lewis and tries to stop the wheels in motion.

Duke is one of most worn GI Joe Costumes.