Fiend

Fiend was among the insults which the Sixth Doctor applied to Astrolabus. (COMIC: Once Upon a Time-Lord)

The Fourth Doctor described as a "fiend who glories in chaos and destruction". (TV: The Deadly Assassin)

Milo Clancey described Maurice Caven as a fiend. (TV: The Space Pirates)

N-Forms that appeared on Earth were believed by humans to be fiends. (AUDIO: The Ghosts of N-Space)

GalSec colonist Krans branded the Sontaran Commander Styre as a "murdering fiend". (TV: The Sontaran Experiment)

H. G. Wells initially believed the Sixth Doctor to be a "foul fanged fiend". The Doctor assured him that he was "not that long in the tooth" and that neat blood brought him out in a rash. (TV: Timelash)