Perpugilliam Brown, known simply as Peri, was an American college student turned companion of the Doctor during his fifth and sixth incarnations.
Peri studied botany and also had an interest in archaeology, fueled by her parents' own passion for the subject. Circa 1984, she encountered the Doctor and Turlough on Lanzarote. The shape-shifting android Kamelion, controlled by the Master at the time, assumed the form of Peri's step-father, Professor Howard Foster, and later that of the Master himself, before seizing control of the TARDIS to take her to the planet Sarn to meet the real Master. After the destruction of Kamelion and the defeat of the Master, Turlough decided to return to his homeworld, Trion, and Peri joined the Doctor on his travels.
After contracting spectrox toxaemia,and then getting accidentally involved in local politics on the twin planets of Androzani Major and Minor, Peri first got abducted by Sharaz Jek, and, upon her escape, began to die from the disease. The Doctor saved her but, not having enough bat's milk (which acted as an antidote) to save himself, regenerated into a very different new and unstable persona. At the peak of his madness, the Doctor attempted to throttle Peri to death - Peri is the only companion known to have suffered a physical assault at the hands of the Doctor. Still, he managed to regain his wits enough that Peri accepted the change enough to continue to travel with him together. Perhaps due to the assault, Peri continued to appear ill at ease with the Doctor from time to time although their relationship became more comfortable as time went on.
In the year 2379, on the planet Thoros Beta, home of the despotic capitalists known as the Mentors, Peri was separated from the Doctor. She met the warrior king Yrcanos from the primitive planet Krontep, who took a liking to her. Kiv, a Mentor, had Peri abducted and taken to his laboratory. The Doctor and the TARDIS were removed from Thoros Beta thanks to the telepathic summons to the Space Station Zenobia, the High Council of Time Lords, so that he could not interfere. As the Doctor watched from Zenobia, Kiv transplanted his consciousness into Peri's body, whereupon Yrcanos burst in and destroyed her body as a form of mercy-killing. Despite the Doctor's horror at learning this, the destruction of Peri's mind and her death had never actually happened. After the defeat of the Valeyard, The Inquisitor revealed that Peri and Yrcanos fell in love and she decided to spend the rest of her life with him.
