Vampires are one of the monsters seen on the whiteboard. They are bet on by the Distribution department.
The first time a vampire is seen is during the elevator scene and later when Hadley and Sitterson are searching the cube prisons for Dana Polk and Marty Mikalski. He is briefly seen on the left screen that Daniel Truman is staring at.
Later on during the System Purge, one of them can be seen on the monitors in the control room, slowly creeping out of the darkness behind a facility worker.A bottle of Vampire Breath summons them.
Vampires are possibly one the most famous horror monsters used in folklore and legend throughout history. They are mentioned in some form or another in virtually every culture on Earth, originally depicted as evil spirits who frequented roads and places associated with death, such as mausoleums and graveyards; however, it was not until the novel "Dracula" by Bram Stoker where they were described as living corpses reliant on the blood of the living to exist, a form which they are known as today. Famous examples include the Vampyre and Dracula. The ones shown in the film are clear references to the look and demeanor of famed vampire Count Orlok in the movie, Nosferatu, who also inspired the Nosferatu-esque vampire character, Kurt Barlow, from Stephen King's novel, Salem's Lot,and its film adaptation.