Trenkor Lep

Most Supreme Captain Trenkor Lep was a Sloathe.

When the freighter hir was on was damaged, hir attempted to attack a group of pirates that attacked the freighter, but was killed by the captain - Nathan li Shao. Trenkor's remains still were animated. After the wreckage of the ship crashed on Planet X, what was left of Lep grew and merged with the planet, growing ever hungrier. To stop the creature formed by this merging, Six sacrificed itself by attacking the TARDIS with hirs phobia-inducing sting. This caused the TARDIS to lash out and kill Six and destroy the thing that had been Trenkor Lep, saving the TARDIS and its occupants. (PROSE: Sky Pirates!)