Grunherz is Voss' love child from a relationship he had with the matriarch of an Iraqi family he saved from the tyranny of Saddam during the first gulf war. He was ordered to bomb a super top secret nuke/ricin/teletubby/jeff foxworthy factory by the CIA, but he realized that dropping his bombs on the factory would decimate the small family dwelling right next to it. So, he landed his jet, loaded the family into the top secret bomb bays on his CIA F-16 (after evacuating the radioactive scorpions). Since the bomb bay was short on room, he loaded the mother into his cockpit with him, and commenced making sweet love to the woman while he successfully bombed the factory and killed Sadaam (the sadaam currently in custody is a clone), and brought her to multiple orgasms. The woman was dropped off in Croatia to protect her from the evil robots from the future who would kill her unborn son if they knew she was carrying Voss' seed. Five months later she gave birth to a 10-year-old son, made possible by Voss' superhuman radioactive sperm, named him Grunherz and gave him up to a Croation family who was moving to the states to further protect his identity.
I only hope that the evil robots from the future aren't reading this post!