Ununpentium (more commonly known as Element 115), is very important in the Nazi Zombies Universe. It is the cause of the zombies and is also used to power the Teleporters, Raygun and Wunderwaffe DG-2. Group 935 tried to harness the powers of Element 115 to power their machines and create super-soliders, which failed horribly and created the zombies. It seems to create a large amount of electricity, as seen by the Meterorite on Shi No Numa, which was used to help create and power the devices and weapons that group 935 were creating.
In the experiments with the Teleporters and Element 115, the hell hounds were created when Edward Richtofen and Ludwig Maxis attempted to teleport Samantha Maxis' dog to one area and back. When it returned, the dog was horribly mutated and became the mother of the current hell hounds found in game.