Vacuum is Xaxon's Nilfiscese (a species from the planet Ivegaffen) form. He appears as an immense, long-necked bipedal creature with a large torso, thin limbs, and large hands and feet. The majority of his body is navy blue and slightly shiny. His head is long, white, and rather oval-shaped. He has three long, thin yellow eyes. His mouth takes up a large portion of his head, and is circular with a ring of teeth. Most of his torso is taken up by a white pad-like material. His hands have very large white gloves, and his feet boots. Attached to each side of his head are two very long, hollow tubes. His Protomnitrix Symbol is on the left side of his chest.
Vacuum's mouth can function like his namesake. He can absorb almost anything into it, everything from dust to cropdusters, from window scrapers to skyscrapers. Unlike humans, Nilfiscese have a third pipe in their throat (the first two, of course, being the esophagus and the larynx) which leads into an organ which converts the materials into sharpened debris. This organ then leads into the tubes on each side of the head. The debris can be forcibly ejected through these tubes to be used as projectile weapons.
- The words Nilfiscese and Ivegaffen are based on an early vacuum cleaner and the inventor of a kind of vacuum cleaner, respectively: the Nilfisk and Ives W. McGaffey.
- Vacuum was based on a very early revision of the alien Upchuck.