Colonel
From X-Files Wiki
Colonel is a military rank and is occasionally used as a shortened form of Lieutenant Colonel. (TXF: "Deep Throat", et al.)
Colonel Mustard was a fictional character. In 1994, upon learning that a bacteria sample she analyzed had been recovered at a crime scene, Doctor Ann Carpenter rhetorically remarked, "We've come a long way from Colonel Mustard in the den with the rope, haven't we?" (TXF: "The Erlenmeyer Flask")
