A self proclaimed genius with a bit of an eccentricity streak, Xar is part of an alien race called the Vortigaunts, living on Earth after a tyrannical alien force dubbed the Combine took over in the aftermath of the Black Mesa incident (in which the Vortigaunts and other Xen species leaked into our world). Despite the state of City 17 under the Combine's rule, Xar seems to be living an alright existence and his life goal is  to be heralded as a genius and make the news.