Crellium

Crellium was an uninhabited planet which consisted mostly of misty swampland.

The Fourth Doctor traced the source of a psychic attack on the Yulians' Communal Will to Crellium, where he and Sarah Jane Smith discovered the body of Krem-ling and his Jukstan servant Marsalla. They learned of Krem-ling's plan to take over the Yulians' Communal Will, allowing him to feed off entire worlds at once instead of one individual at a time. The Doctor was unable to stop the emissaries of Drakka from reviving, but convinced Marsalla to turn against Krem-ling and destroy the emissaries. (PROSE: The Vampires of Crellium)