Origin

Alien species that can change form and powers to mimic exactly those they come in contact with.

Creation

Written by Larry Lieber and drawn by Al Hartley.

Major Story Arcs

The Xartans attempt to invade Earth by posing as lawmakers that will make crazy laws to disrupt the citizenry and ultimately lead to a noble overthrow. Thor stops them by hurling their leader Ugarth into space and forces the remaining Xarthans to transform into trees with the hope that as trees, unable to think, the Xarthans will be unable to change forms. Unknown to Thor, however, is that dormancy causes a natural return to the Xarthanian form. The aliens regroup.

Seeking revenge for his father's death, as well as wanting to take his homeland back, Lord Zano enacts a plan in which his minions steal body templates from Thor and his Avengers. The aliens take their forms and powers and attack a spaceship that they hope to be in their attacking armada. The ship is Ship, however, and belongs to X-Factor. The Xartans seem to have the upper-hand until the wards of X-Factor show up to help in the fight. After defeat, the Xartans are placed in stasis by Ship.