Belathauzer was created by David Anthony Kraft and Ed Hannigan in 1978 and first appeared in The Defenders # 58.
Belathauzer was one of the leaders of a race of demons that tried to take over the Earth in an event called Xenogenesis. Vera Gemini led the cult, called the Harvesters of Eyes, that brought them to Earth.
They took human forms and roles. Balathauzer took the form of a US Air Force General, and used Air Force jets to attack the Defenders. However, they managed to escape.
Vera Gemini managed to manipulate the demons, and became their leader against their will.
Eventually the demons were all sent back to their realm by the Defenders.