First appearing in Fantastic Four #261, Xxan is a survivor torn between avenging his planet and acting as an alien delegate. When Richard Reed is put on trial for the suspected destruction of the Skrull home world, the rest of the Fantastic Four (Susan Storm, Johnny Storm, and Thing) are greeted by Xxan Xxar. 
 
During Reed's trial, Xxar prepares to take Galactus' life (who also happens to be at the trial in defense of Richards), but abandons the plot, fearing the small gun may only annoy the behemoth.