Godfrey (Curtain Call)

 was an alien who impregnated Agatha Ellis.

Agatha met him at Tesco one day and they went out on a date. They slept together on the second date and Godfrey left her after that. Four months later, he appeared in her room at night, his eyes glowing silver, and the baby in her womb glowed as well.

When Agatha was sent to a home, Godfrey visited her and tried to take the baby when it reached full term, but he was defeated by the Sixth Doctor. (PROSE: Curtain Call)