Rogue Angel

A Weeping Angel, whom Claire Brown came to refer to as "her" Angel, was an instrument of the Division until it ran away, containing within itself a complete record of Division's history — including the memories extracted from the Doctor when they were retired from the Division and regressed into a child. It hid inside the psychic Claire Brown in the 1960s and lured the Thirteenth Doctor to her, offering her to the Division's Extraction Squad as a better target than itself.

History
First invading the time storm in the Doctor's time stream, the Angel began chasing Yaz around time, first going after her in a memory of a lunch break during a police round. It would later follow her to an unlived memory of playing video games with her sister Sonya, appearing inside the game itself, emerging into the living room until Yaz smashed the gaming console. It later presented itself on the screen of her phone, it gained physical form and started altering the TARDIS's destination. (TV: Once, Upon Time) towards a village, where Claire Brown had been sent to by another Angel.

When the Doctor got inside Claire's mind, it told her how it had once been a part of the Division, much like the Doctor herself and how it was on the run from the rest of the Angels for having knowledge. However, its true purpose was to offer the Doctor to the Extraction Squad as an even more valuable target, in exchange for them not taking it. The Squad agreed to this trade, letting Claire's angel go while turning the Doctor into a Weeping Angel. (TV: Village of the Angels)