Figment

Figments were creatures on Darbodia that gave the inhabitants imagination. In a dream, Wargonn captured them all, since he believed they made the people disorderly. The Eighth Doctor forced Wargonn to release the figments, restoring imagination to the Darbodians. (COMIC: The Land of Happy Endings)

Behind the scenes
It was later established that the adventure was part of the Eighth Doctor's dream, therefore it is unknown if these creatures actually exist.