As one of the oldest living Jägers, General Goomblast sees a larger picture than the average Jägermonster. He is tall even for Jager, has an exceptionally enormous toothy mouth, goggles and a metal cap apparently riveted to his skull.
Along with his fellow Jägergenerals Khrizhan and Zog he is one of the troika who run things Jägerish aboard Castle Wulfenbach (where Klaus can in turn keep an eye on them), not to mention the rest of the Wulfenbach empire.
He gets along well with Agatha (whom he presumably at least suspects is a Heterodyne even before meeting her ) when she is brought over for tea and discreet questioning aboard the Castle. He in fact seems downright personable, staying out of the growing argument between his two fellows and ushering Agatha out of the room until he is accidentally hit on the head with a tossed chest; the resulting eruption causes rank-and-file Jager André to quickly depart the scene with Agatha.
Goomblast's weapon is a long rapier, which he uses during the Siege of Mechanicsburg to defend the defecting Vespiary Squad from attacking Wulfenbach forces. Along with most of the other Generals, he is trapped in the city when Klaus sets off his Take-Five Bomb.
The novelization Agatha H. and the Airship City adds the information that he has perfected a very graceful courtier's bow, and speaks in a rather surprising contralto voice.