Zeron (The Enemy from Nowhere)

The Zerons were an advanced telepathic species whose bodies were made of reverse matter. They normally appeared as small white spheres, but could form into large humanoid bodies.

In the 1970s, the Zerons came to Earth to convert it to reverse matter and claim it as their own. The approach of their spacecraft was detected by Davie Jenkins at Downphilly and by a recently launched American space station, but could not be seen with optical instruments due to its atomic structure. Not realising the nature of the object, the crew of the space station launched nuclear missiles at it, which failed to destroy it. The Zerons destroyed the space station and brought its crew on board as captives, then fired a ray which destroyed part of Downphilly. The Third Doctor and Jenkins took the TARDIS on board the spacecraft and confronted the Zerons, who told them their plans and arrogantly dismissed them as a potential threat. The Doctor and Jenkins rescued the station's crew and constructed a bomb from the station's warheads which destroyed the Zerons and their ship. (COMIC: The The Enemy from Nowhere)