Home Planet: Unknown
Life Form: Crustacoid
Info: The original Macras were large, able to hold a human in one claw. They were stocky in build, with large eyestalks and large claws. Although they grew over the years and became hundreds of times larger, their intelligence devolved into something much more animalistic.
On one planet, the original Macra's used the Humans as slaves to mine the gases that were vital for their existence. And on New Earth a colony of Macra escaped from the zoo when the power broke down and made their way into the Motorway where they lived on the fumes.
Episodes appeared: The Macra Terror, Gridlock
Home Planet: Midnight
Life Form: Unknown
Info: A mysterious, unnamed, and unseen creature, found on the surface of a diamond planet where supposedly no life can ever survive.
It is now believed that the creature is dead, having perished while possessing Sky's body. However, since no one can ever venture out onto the planet, its true fate is unknown.
Episode appeared: Midnight
Home Planet: Nestine Homeworld
Life Form: Liquid plastic-substance, squid-like creature, or illuminating orb
Info: The Nestines were an extraterrestrial, disembodied gestalt intelligence which first arrived on Earth in hollow plastic meteorites. They're among the oldest beings in the universe, described as creatures which existed in the "Dark Times". Their most recent Earth invasion was due to their food supply running out due to a war.
The Nestine's have attempted to take over Earth several times, using their technology to animate shop window dummies (Autons) and other plastic objects and form them into weapons. This control was described as "warp shunt technology", and was formed through telepathic projection. It is believed that the Nestines were aware of the Time War, possibly loosing their planet because of it.
Episodes appeared: Spearhead from Space, Terror of the Autons, Rose
Home Planet: Ood Sphere: Horsehead Nebula
Life Form: Squid-faced humanoid
Info: In the distant future, the Ood are a slave race to humanity, performing menial tasks, and it is claimed that every human has an Ood servant.
As well as their low level psychic resonance, the Ood have also shown to be able to roughly predict the future. It appears that no Ood has a chosen name, or if they do, it is never spoken out loud. The only known Ood to be referred to by name was Ood Sigma.
Episode appeared: Impossible Planet, Satan Pit, Planet of the Ood
(Sixth part continued here: P-R)