Xenos is a supervillain from Marvel comics and an enemy of Moon Knight.
Sgt. Gwenn, a 14-year veteran police officer whose politics were of the extreme right-wing, was overcome by xenophobia. In his basement, he kept rats within a model town, dressed them in doll clothes, and referred to them as his army. Convinced that foreigners were responsible for ruining America by taking jobs away from "real" Americans, he embarked on a one-man crusade to kill as many foreigners as he could.
His first known assault occurred at JFK International Airport; dressed in a white cloak, he shot Japanese Trade Minister Sakata in the arm. Quickly changing to his normal clothes, he then claimed that the assassin had been Moon Knight. His superior, Lt. Flint, believed him and set off a manhunt for Moon Knight. In the midst of his escape from Gwenn and Flint, Moon Knight saved an Indian woman from being struck by a broken tree branch, an incident which disgusted Gwenn.
Seeing that Moon Knight was not as pure as he had believed, Gwenn now donned a new uniform, emulating a rat and attempted to complete his unfinished attempt on Sakata. However, this time Moon Knight was present and saved Sakata's life.
Trailed back to his basement lair by Moon Knight, Xenos set his army of rats upon him, but Moon Knight managed to escape. In final conflict, Moon Knight tore off his mask and make-up, and revealed Xenos as Sgt. Gwenn. As they tussled, they fell through a skylight, and Xenos escaped into the shadows, with an axe in his hand. He nearly assassinated Moon Knight, but his presence was given away at the last minute when, ironically, he stepped in a mouse trap.
In the aftermath, Flint apologized for suspecting Moon Knight.