Klaus was a mercenary and a member of Max Stafford's private military team. In 2004, Stafford's team was hired by Charles Bishop Weyland to accompany a Weyland Industries expedition to Bouvetøya, Antarctica. The expedition's objective was to investigate an ancient Pyramid buried beneath the ice there, with Stafford's team present to provide security. The Pyramid was discovered to be a Yautja temple and hunting ground where the Predators would breed Xenomorphs for use in their Hunts, and the expedition soon became caught up in the battle between the two species.
Klaus was killed when the Predators raided the expedition's surface camp.
When the majority of the expedition's personnel descended to the pyramid beneath Razorback Point, Klaus was left on the surface to help keep the team's base camp secure, both from any external threats and against the severe storm that closed in on the island. While out on patrol, he became aware of someone or something stalking him through the blizzard. Despite drawing his weapon, he was quickly ambushed and killed by one of the Yautja.
Klaus carried a nickel-plated Desert Eagle fitted with a lime green laser sight during the expedition to Bouvet Island.