Beck (The Lady in the Lake)

Beck was one of at least 8 clones created by Madame Kovarian on Demons Run after she stole Melody Pond's embryonic DNA. After the Eleventh Doctor raided Demons Run, Beck escaped on a ship with the other six clones. As part of his religious cult, Lake convinced her to die multiple times on Terminus Prime so he could covertly study regeneration and find out how long he was able to live. (AUDIO: The Lady in the Lake)