Bygone Horde

From Tardis Wiki, the free Doctor Who reference

The Bygone Horde were a collection of species who were erased from existence during the Last Great Time War. However, the memory of them survived and they were left as echoes displaced from time on a plane of non-reality. It was in this reduced state that they banded together before beginning to emerge on Earth where they planned to return to existence by sacrificing the human race. They were thwarted by the Ninth Doctor and Adam Mitchell. (AUDIO: The Other Side)