Forever Dragon

The Forever Dragon is a large dragon that appeared in the episode Medievel Evil of Ben 10: Unlimited Force. The character is actually unnamed, although many fans of the show reffer to him as the "Forever Dragon".

In Ben 10: Unlimited Force
The Forever Dragon's first (and currently only) appearance in Unlimited Force was in Medievel Evil, where it was reactivated and controlled by the Forever Knights. However, near the end of the episode, the dragon was defeated by Waybig and sealed away. It is not confirmed if the dragon will have any other appearances in the series.

Trivia

 * The Forever Dragon resembles Diagon's dragon form, which appeared in Sir George's flashback in Solitary Alingment.
 * Enoch said that the true name of the dragon is one that cannot be pronounced by other than a Forever Knight, though no Forever Knight has ever said his true name in the episode.