Zagreus sits inside your head. Zagreus lives among the dead… Zagreus sees you in your bed and eats you when you're sleeping.
Zagreus was a Monster in a Gallifreyan nursery rhyme from Doctor Who. It was the name given to Anti-Time. The Neverpeople, led by Sentris, created a story of Rassilon travelling to the Antiverse to battle Zagreus as part of their plot to destroy the Web of Time. However when the Eighth Doctor was infected by anti-time he became an an aggressive figure that called himself Zagreus. The TARDIS was also infected by anti-time and formed an alliance with Rassilon, who planned to use the anti-time to destroy the Divergence. He melted down the outer shell of the TARDIS in his Foundry and the Doctor under the influence of Zagreus used the anti-time metals to form a sword, with which the Divergence would be cut out of time. However he was stabbed by his companion Charley Pollard. He survived by giving into his Zagreus persona. Zagreus refused to be ordered by Rassilon and hurled him into the Divergent Universe. The TARDIS meanwhile was freed of the Anti-Time infection and used pure zero matter to restore the Doctor. However as there were still traces of Anti-Time on his person the Doctor briefly exiled himself to the Divergent Universe.