M is for... Meglos

Meglos' natural form resembled a large xerophyte plant - a cactus. However, it existed as a wavelength of light so could take on other forms.

It was the last surviving member of the Zolfa-Thuran race, a war-like species which had wiped itself out in galactic warfare. Trapped immobile in a control centre on its home-world, it required a host body to transfer into to move around. It hired a group of Gaztak mercenaries, led by General Grugger, to abduct a human being from Earth as part of a plan to retrieve its missing power source. This was the 12-sided crystal Dodecahedron, which had been jettisoned into space and found its way to the neighbouring planet of Tigella.

There, it had been used as a power source but was also worshiped by a religious faction known as the Deons who thought it a gift from their god Ti.

Meglos wished to get it back in order to power an energy weapon capable of destroying a planet. His control centre was surrounded by giant shields which acted as a focus for this weapon. On learning that the Doctor had been summoned to Tigella to help its leader, Meglos devised a plan to waylay him in a Chronic Hysteresis time-loop then take on his appearance - using the abducted human as a template for this. He would then go to Tigella and steal the Dodecahedron, with the blame being placed on the Doctor.

His control over the Earthling sometimes slipped as the man struggled to break free, so that his flesh took on a green, spiky, cactus-like appearance.

After successfully regaining the Dodecahedron, Meglos decided to first of all destroy Tigella. The Doctor imitated him to sabotage the weapon, and Grugger and his men confused the two and locked up both. They escaped, but Meglos was killed along with the Gaztaks when the weapon self-destructed.

Voiced by: Crawford Logan. Played by: Tom Baker and Christopher Owen. Appearances: Meglos (1980).

• Crawford Logan also played the Tigellan Savant Deedrix in the story. 
• Christopher Owen played the abducted Earthman, who is named George Morris in the novelisation.
• Gareth Roberts seriously considered having Meglos return in his Series 5 story The Lodger. He changed his mind as the humanoid version of Meglos might look too much like the Vinvocci, which had only recently appeared in The End of Time.