Wirrn Queen
From Tardis Wiki, the free Doctor Who reference
A Wirrn Queen was essential to the life-cycle of the Wirrn. She would lay an egg in a host creature. The host would be eaten when the larvae hatched.
Aboard Nerva Beacon, a Wirrn Queen attempted to find a host but was shot by an auto-guard. She disabled the device and managed to lay an egg in a human, Dune, before dying in the cryogenic chamber where Harry Sullivan later found her. (TV: The Ark in Space)
