In the intro of Army Men: Green Rogue he is shown with a massive amount of soldiers, tanks, and helicopters and states "with Sgt. Hawk and those blasted heroes out of the way, the Green Nation doesn't stand a chance" then signals his men forward.
He is seen in Army Men: Sarge's Heroes 2, where in one mission the player must infiltrate a Tan base and capture him alive. He is captured and is about to sign a peace treaty with the Green Nation when Plastro bursts in and kidnaps Vikki Grimm, stopping the signing. It is unknown what happens to him next, though it is assumed that Plastro is either angry with him for signing a treaty and kills him, he escapes back with the Tan army to continue serving as a commander, or he completely escapes from everyone.
Tannenburg has a German accent, an abnormally long face, and is tall and lean. He wears a monocle on his left eye and speaks in a dark tone.