|Citizen of an extinct planet.|
|Nation or Planet of Origin|
|Base of Operations|
|Unnamed asteroid field.|
Gaseous alien shape-shifter capable of assuming the physical attributes of others including super humans.
Adventures of Superman
Green Lantern Vol. 2
|Green Lantern Vol. 2 #108 (Sept. 1978)|
|Dennis O'Neil & Mike Grell|
Millions of years after the destruction of its planet the alien known as Xum found the perfect world to reestablish its race - Earth. In order to make the planet inhabitable for the gaseous alien's race the first step would be to destroy the ozone layer - an act that would cause mass extinction. To better acclimate and protect itself Xum assumed a solid form mimicking the appearance and powers of the Justice League - as the alien invader called Replikon.