Carrie (Something Borrowed)

"Carrie" was a female Nostrovite. She was the mother of another Nostrovite's child, who implanted an egg into Gwen Cooper to incubate it. She disguised herself as a guest at the wedding of Gwen and Rhys Williams to forcibly take her child. Rhys destroyed the child with the singularity scalpel and she was killed by Captain Jack Harkness. (TW: Something Borrowed)