Rent Doctor Who: State of Decay (1980)

The Doctor (Tom Baker), Romana (Lalla Ward) and K-9 (voice of John Leeson) are trapped in E-Space, a strange alternative universe. They are unable to find an escape, and do not realise that a young boy called Adric (Matthew Waterhouse) has stowed away aboard the 'Tardis'. Arriving on a primitive planet where the local inhabitants fear the Three Who Rule, they soon find themselves facing a hideous creature from Time Lord legends. Long thought dead, the Doctor must confront a blood-sucking monster that is very much alive...