Doctor Who: EVERY NuWho Villain And Monster Ranked Worst To Best
38. Gus
Appears in: Mummy on the Orient Express.
If movies and TV shows have taught us anything (quite a lot as it goes), it's that artificial intelligence has a flare for the nefarious, as efficiently demonstrated by the disarmingly-voiced Gus.
He rounds up the Doctor and those with your bog-standard human intelligence (no offence Perkins) and essentially gives them an ultimatum: unravel the Foretold's true purpose or end up dead.
Despite kindly offering grief counseling after the demise of Professor Moorhouse, Gus provides a timely reminder of the old adage that you should never mess about AI with an agenda by jettisoning the kitchen crew into space after the Doctor had disregarded Gus' explicit orders to stop talking to Clara on the phone.
Eventually, it tries to dispose the time-travelling duo and the remaining passengers as soon as the Doctor does his thing and works it out. Then, just after he does his other thing by teleporting everyone to safety, he tries to hack Gus to find out who was really behind the "exciting" enterprise, but the computer derails the Doctor by blowing up the train.