Amphibious Assault Guns are Cobra amphibious tanks. They are armed with their main turret and land torpedoes.
Cobra Commander deployed a group of S.E.A. Legs backed up by amphibious assault guns in an attack designed to stop the space shuttle from deploying a satellite that has the ability to detect their future network of Undersea Bases. G.I. Joe's outer ring of defense were able to stop all of the S.E.A. Legs, but some of the Amphibious Assault Guns were able to penetrate the outer defense only to be destroyed by the inner ring of defense. One Amphibious Assault Gun was successful in disabling the M.O.B.A.T. with a land torpedo, but the M.O.B.A.T.'s main turret was still working allowing it to blow up an Amphibious Assault gun. Others were taken out by Zap's missile launcher, Short-Fuze's mortar, Scarlett's handbag bomb, and Snake-Eyes's karate chop.
However, while the Joes were busy fighting them off, Cobra Commander was able to fire off a missile in his Submersible Helicopter but Hawk shot the missile down with a rife before it could damage the Space Shuttle.