A dragon that appears in Be-Knighted which is held captive by the Forever Knights. Little is known other than that it is the model for the Forever Knight's Robotic Dragon and that it is the goal of the Forever Knights to control it which was likely the reason they sided with the Highbreed, to get a weapon powerful enough to keep it at bay/control it. The Alien Dragon is a map maker that wanted to kill The Forever Knights, but Ben managed to convince him and he choose to leave on his spaceship instead.
The Alien Dragon has made one appearance in Ben 10: Alien Force.