Krohg

Krohg was a glih and the control nexus for the Skel'Ske.

After Doc Dantalion erased Powerless Friendless' memories of his life before coming to Earth, the Hith kept Krohg as a pet, using it to help him commit petty thefts. When he had his memories restored later and snuck back on the Skel'Ske with some of the Seventh Doctor's companions, Bernice Summerfield realised what Krohg really was and activated the ship. Powerless Friendless, not wanting to be responsible for more deaths, crashed the Skel'Ske into the Undercity, destroying it and the nexus so they could not be used as a weapon. (PROSE: Original Sin)