Never-were

The Never-were were a race of humanoids who existed in an alternative reality. They invaded the dreams and mind of Amy Pond whilst she was inside the TARDIS travelling through the vortex. They guided Amy into piloting the TARDIS to an alien planet.

They intended to use Amy to destroy the Queen of an insect race which would prevent their world from coming into existence. However, Amy's will was too strong and she refused to kill an innocent creature. (COMIC: Ghosts of the Never-were)