The Koggnossenti were an intelligent humanoid species.
They had curvy hands with spindly fingers, giant heads, grey skin and red eyes. In 2011, a Tech-squadron of the Koggnossenti invaded the Earth with the intention of conquering the planet by reducing the intelligence of humans so they would be frightened of their own technology and thus be unable to fight back. They arrived from another dimension in a Hubship, from which they could reach London Underground.
Their hubship was self-destructed after their intelligence wave was backfired onto them until they could no longer understand their own controls. They triggered the engines, which detonated the ship through at least 'six or seven dimensions', according to the Tenth Doctor. (AUDIO: Technophobia)