A is for... Axos

A parasitical creature which absorbed victim worlds of all their energy. Axos appeared to be a spacecraft, organic in nature. It would land on a planet and its crew would appear as idealised versions of the dominant life-form. The inhabitants would be offered a substance called Axonite, which it was claimed could solve almost any problem the planet faced - from new energy supplies to extra food. Once spread across the planet, the Axonite would be activated to expand and begin absorbing all energy.

Axos was brought to Earth by the Master, after it took him captive. The Doctor noticed that the craft was able to time-jump briefly as it approached the planet - in order to avoid a missile strike. The crew - who identified themselves as Axons - appeared as beautiful golden-skinned humanoids. They claimed that they needed time for Axos to regenerate, and offered Axonite in return. The Doctor was suspicious that they had lost their homeworld to solar flare activity, as Axonite should have prevented this. Axos abducted a tramp and absorbed his life-force when it realised that he was of no value to it. It also captured agent Bill Filer, who was visiting UNIT HQ, but he was kept alive as he could be used later. An Axon could alter its appearance to look like him, In their true form, Axons were lumpy, tentacled masses, which could kill with a powerful explosive charge. The Axons exploited the greed for power by a civil servant, and the greed for knowledge by a scientist, to ensure that Axonite was spread across the planet - helped along by the Master. The Doctor deduced that Axos, the Axons, and Axonite were all part of the same organism.

Axos wanted the ability to travel through time, in order to increase its feeding range. The Doctor was kidnapped, and Axos was able to read his mind - breaking through the blocks imposed by the Time Lords when they exiled him to Earth. To get sufficient power, an Axon entered the reactor of a nuclear power station to absorb energy. The Master was forced to help UNIT to stop this, and an attempt to channel the energy into Axos in one huge blast failed to destroy it. When the Doctor escaped, he allied himself with the Master against his friends - or seemed to. He offered Axos the time travel it wanted, by linking it to the TARDIS, but then tricked it into entering a time-loop in which it would be trapped forever.

Appearances: The Claws of Axos (1971). Played by: Bernard Holley (Axon man and voice of Axos); Patricia Gordino (Axon woman): John Hicks (Axon boy): and Debbie Lee London (Axon girl).