Crozier
From Tardis Wiki, the free Doctor Who reference
Crozier was a bio-engineering scientist hired by the Mentors to perform life-saving surgery on Kiv. In a fake version of events, he swapped Peri's thoughts for Kiv's thoughts. This was later proved to be a fake, masterminded by The Valeyard. (DW: Mindwarp/The Ultimate Foe)
