The Fisher King
The work that went into the look of this alien was sadly underused in the episode with a brief dialogue with the Doctor followed by a sudden demise. Don’t get me wrong the episodes were good, the ghost plotline was well carried off, just a shame the ultimate villain didn’t get much screen time.
The Fisher King was a leader of a species which conquered several worlds including Tivoli. Fearsome in stature they possessed powerful weaponry and technology that could use the dead as a means of communication, conjuring ghosts that send out an endlessly repeating message.