The Doctor's grandmothers
From Tardis Wiki, the free Doctor Who reference
The Doctor, according to their thirteenth incarnation, had seven grandmothers.
Their favourite was Granny Five, who told a young Doctor bedtime stories about the Solitract when he was having trouble sleeping.
Granny Five also claimed that Granny Two was a secret agent for the Zygons. (TV: It Takes You Away)