Perpugilliam (Peri) Brown was an American botany student, who met the fifth Doctor and Turlough on a Greek island, after her step-father found a Trion artefact (Planet of Fire). She was infected by spectrox and almost died, if not for the fifth Doctor giving her the only antidote in The Caves of Androzani. Strong-willed and somewhat stubborn, she never entirely allowed the Doctor to get his own way.

She was captured and almost killed when the mind scientist Crozier put Kiv's mind into her body. (Mindwarp) She was rescued by King Yrcanos and went back to his home planet, Krontep as his queen

Nicola still attends conventions and has reprised her role as Peri for Big Finish on CD.