Racnoss

The Racnoss were an ancient race from the Dark Times of the universe who re-emerged after billions of years to threaten Earth in 2007.

Appearance
The Racnoss looked like large half-humanoid, half-arachnid beings, with blood-red skin and a crested skull. They had three pairs of eyes - one pair in the place where humans have theirs, and the remaining ones on the forehead. Their armour was tough and shed frequently. They had ten razor-tipped limbs, two of which they used for arms (presumably to also cut web). They had spinnerets at the base of their abdomen, allowing them to produce miles of webbing. (TV: The Runaway Bride, REF: Doctor Who: The Visual Dictionary)

Life cycle
The Empress of the Racnoss could be identified by the crown-like structure on her head. (REF: Doctor Who: The Visual Dictionary) She apparently was the one who had the duty of laying eggs, which hatched into other Racnoss, meaning that the entire Racnoss race were the children of the Empress. The young were born starving, and so invaded planets to feed off all life on them. (TV: The Runaway Bride)

Technology
Most of Racnoss technology was made of a fine, silk-like substance, strengthened and powered by Huon energy, including their spacecraft, amongst other things.

The Webstar had energy weaponry which was used to kill for meat. It also had scanning equipment which the Empress of the Racnoss used to watch a planet and a teleporter to allow her to travel to and from the planet. (TV: The Runaway Bride)

History
The Racnoss evolved in the Dark Times of the universe. (TV: The Infinite Quest) They were nearly wiped out by the Fledgling Empires over 4.6 billion years ago. Nearly all of the survivors of the race escaped in their spacecraft, around which the planet Earth would later form. The Empress of the Racnoss stayed in her Webstar, but also went into hibernation at the "edge of the Universe" until she decided to search for her young.

Around 2007, the Torchwood Institute began a drilling attempt to the centre of the Earth. This awoke the Secret Heart, which in turn signalled the Empress of the Racnoss. She came to Earth and took over the work site after the destruction of Torchwood One during the Battle of Canary Wharf. She used the River Thames as a method of manufacturing Huon particles to awaken the Racnoss and took over the pilot fish to use as soldiers. She was presumably killed indirectly by the Tenth Doctor when he used her own weapon again and burnt her into pieces. (TV: The Runaway Bride)

Other references

 * It was believed that a splinter nest of Racnoss may have been the ones that attacked the makers of the Clades. (PROSE: Peacemaker)
 * Jack Harkness speculated that an interaction with the Racnoss hibernation field's huon particles may have resulted in the Blessing, but was forced to admit he had no idea. (TV: The Blood Line)