DC is a black cat, its gender unknown. As was common in the 1800's, the nation's capitol was infested with rats. Cats were brought in to wander the corridors and catch the rats. DC is thought to be descended from those days for it is a fierce looking animal seen roaming the hallways looking for prey.
Many people, especially security guards, have encountered Demon Cat over the years. The feline only appears at night and has only been seen when the viewer is alone.
"One guard who saw it wants to remain anonymous. It happened on a January night in the 1970s. As he was walking through a passage way, he saw the black cat approach. The phantom appeared to get larger as it walked toward him. Its eyes had a reddish glow. The guard was afraid to move. Finally, the phantom reached the size of a tiger and its meowings changed to roars. It crouched and sprang and all the guard could do was to pray and close his eyes. Nothing happened. When the guard opened his eyes, the cat had vanished.
He told only a few trusted friends about the incident because he was afraid that people would think he was insane or that he had been under the influence while working, either of which he feared would cost him his job."
One more thing. Demon Cat has reportedly been seen before the change in administrations. Keep an eye out for DC in 2012!