Once an actor joins the coveted realms of the Doctor Who universe, they're pretty much guaranteed to have an ever growing and dedicated fan base for life. By the time they leave the TARDIS behind them, there's no doubt that they'll go on to achieve bigger and better things, purely because they've got a legion of devoted followers who are ready and waiting to quite literally watch anything and everything they're subsequently in. Sometimes, though, that commitment is easier said than done. Doctor Who is watched by millions week in, week out (well, when it's actually on, at least - is it the autumn yet?!) so it's understandable how its cast members become so heavily associated with their respective roles. For the children watching (and probably even for some adults, too), they are their characters which makes it exceptionally difficult to accept it when they pop up in other shows playing other people. Don't get us wrong. Usually watching your favourite Doctor Who actors take on other parts is an enjoyable experience for all concerned, but usually their on screen shenanigans are enough to send a shiver down your spine, whether that's because it's particularly cringeworthy, you can't stop associating them with Doctor Who or they do something in their new role that completely tarnishes their previous reputation as a coveted time traveller. Here are 8 such examples of roles that Doctor Who alumni have taken on which pretty much destroyed every Whovian soul from here to Gallifrey. Brace yourselves, because this ain't gonna be easy. They're not in the TARDIS anymore, Toto.