John Sessions
From Tardis Wiki, the free Doctor Who reference
John Sessions (born John Gibb Marshall on 11 January 1953) is a RADA trained actor, comedian, and sometimes panelist on British quiz comedies. He is particularly well known, at least in Britain, as one of the original regular panelists on Who's Line Is It Anyway?, and, more recently, as a recurring guest on QI.
As of 2010, he has lent only his voice to Doctor Who. Alongside Colin Baker, he was several characters — notably Mozart — in My Own Private Wolfgang. He later starred opposite Peter Davison in Castle of Fear as Roland of Brittany. In the same play, he also notably played the Fifth Doctor in the piece's play-within-a-play.