The Nimon

The Nimon resemble the mythical Minotaur, these black bull-headed monsters were actually a technologically advanced race who existed by draining planets of their energy, having first seduced the naive population with promises of power. In the centre of a maze on Skonnos the Nimon transported his fellows from the planet of Crinoth (which was sucked dry by the Nimon) to Skonnos where they were killed in an explosion.

The Hymetusite is the most radioactive substance in the galaxy which was brought to Skonnos as a tribute to the Nimon and used to fuel their space capsules. Skonnos was once the heart of the great Skonnan Empire, this fading planet was offered power by the Nimon in the exchange of regular tributes. The Doctor saved the planet from extinction by destroying the Nimon's power complex and the transmat terminal on Skonnos.

The Nimon only appeared in The Horns of Nimon.