Thrayne
Thrayne, also known as Chilton, was a long-lived alien from Cyntheros posing as a scientist at a research base in Devon, supposedly researching superconductivity. In reality, he was determined to hunt an Icewalker, as a way of leaving an exile imposed upon him by his people. In the 1970s, he showed the Third Doctor, Alistair Gordon Lethbridge-Stewart and Sarah Jane Smith around the facility and demonstrated one of the experiments, which contained an alien material, which concerned the Doctor.
After the experiment went wrong, he hunted the Brigadier whilst the Doctor and Sarah travelled back to 1855, discovering Chilton - then going by his true name - exploiting the local nobility of Devon to try and hunt the creature. After the Doctor foiled his plans in 1855, him and Sarah travelled back to the present, wherein the Brigadier had corned him with the help of the Icewalker. He was then taken into UNIT custody and 'put on ice', according to the Brigadier. (AUDIO: The Devil's Hoofprints)
