Saibra
Saibra was a mutant human who would replicate a person when touching any part of their organic matter. She also wore a hologram shell to help replicate clothing.
As she was unable to control this ability, she helped the Twelfth Doctor rob the Bank of Karabraxos in order to gain a gene suppressant which would remove her powers. During the mission, she briefly impersonated Clara Oswald to demonstrate her power and impersonated a businessman named Mr Porrima to facilitate entering the bank, before copying a security guard to rescue the Doctor and Clara after they were captured. After the mission was successfully completed, Saibra shared a takeaway with the others before being returned to her own time and place, having used the gene suppressant. (TV: Time Heist)
References
As one of the people she had met during her travels with the Doctor, Saibra was included in a series of notes written by Clara when she was planning to confess to Danny Pink via phone call about her adventures with the Doctor. (TV: Dark Water)