Dr. Brian Clauss was part of the seven-man scientific team aboard the United Systems Military vessel USM Auriga that successfully cloned Ellen Ripley in order to recreate the Xenomorph species.
Clauss was present during the operation to remove the Chestburster embryo from Ripley 8. Ripley 8 badly broke Dr. Sprague's arm as he attempted to closing her incisions, Clauss assisted in the surgery to repair the damage.
When the Cloned Xenomorphs later escaped captivity, Clauss was one of the first to arrive on the scene. He immediately discovered several soldiers who had been knocked unconscious, apparently spared to later be hosts for more Chestbursters. After shedding his lab coat and arming himself, he cautiously entered the chamber where the first Xenomorphs had escaped. However, the Lead Alien was waiting outside, once Clauss was inside the holding cell it activated the nitrogen spray deterrent, drenching him in liquid nitrogen and causing his now brittle body to shatter and crumble.
- Clauss is never named in the film; his name is taken from the novelization. Even though he is credited as a soldier in the movie ("Frozen soldier"), the novel makes it clear he is part of the science team; in the book, before he enters the chamber where he dies, he removes his lab coat to reveal his military fatigues underneath, explaining his appearance in the film.
- The sequence in the book where Clauss discovers several apparently comatose soldiers in the Xenomorph holding area apparently references the novelization of Aliens, wherein the Xenomorphs sting people with their tails to render them unconscious before taking them to the Hive to be cocooned.