Androkan
Medicus Androkan was a Gallifreyan scientist during the Dark Times. He took great interest in the Ninth Doctor's Time Lord DNA, and later assisted him in escaping the shadow planetoid. He was surprised to learn that the Doctor was a time traveller, as the concept was entirely novel during the Dark Times, and successfully guessed that the Doctor was a future Gallifreyan.
After infiltrating a Coffin Ship and being captured by Drogann, he was killed by Friar Grystok due to his apparent uselessness for blood consumption. However, his previous blood analysis of Rose Tyler allowed the Doctor to later make a substitute blood supply that would help free the captive vampires on the ship. (COMIC: Monstrous Beauty)