Demon ( The Relics of Time ) The Demon was an extra - dimensional being hired to set up the planetoid Sepulchre and trap the Fourth Doctor in it . To accomplish this , the Demon staged historical conundrums to get the Doctor to accompany ( or follow ) him to Sepulchre . If the Demon carried a name of his own , he refused to give it . Description . In most of his appearances the Demon took the form of various figures indigenous to the times and places of his traps . He eventually revealed his true form of a large creature with dark purple skin , silvery wings , horns , cloven hooves and a forked tongue . The Demon referred to himself as coming from a place outside the universe we know : " My home is a tiny backwater in a shadow dimension . A place bearing practically no resemblance to this physical universe . " ( AUDIO : " Sepulchre " ) He also refused to offer any real name for himself , stating it would mean nothing to the Doctor . Powers . Having come from a different dimension , the Demon considered time to be just another dimension , one among many . The Demon was for all intents immortal . He had a natural ability to change shape and affect the minds of others , though he needed to drain the life force of others to sustain these powers . ( AUDIO : " The Demon of Paris " ) In addition the Demon possessed a high amount of dimensional and psychic technology , which he used to create the Sepulchre atop a planetoid on the edge of the universe . He was able to take pieces of the Doctor ' s spatial geometer and combine it with cultist chanting to generate a telepath debilitator . ( AUDIO : " Starfall " ) He also possessed and used his own primitive version of a TARDIS to move around in time and space . ( AUDIO : " Sepulchre " ) History . Traps for the Doctor . Having agreed to trap the Doctor , the Demon stole the Doctor ' s spatial geometer , leaving behind a bag with five objects as clues . The first one , the tile from a Roman mosaic , led the Doctor to Celtic Britain , where the Demon had taken the identity of the Roman Emperor Claudius . Attempts to usher the Doctor inside the back reaches of his tent failed , and the Doctor escaped . ( AUDIO : " The Relics of Time " ) Next , the Demon used an altered version of a poster painted by Henri de Toulouse - Lautrec to lure the Doctor to Paris in the 1890s . In the guise of Lautrec ' s Concierge he tried to frame Lautrec as a murderer of street girls , in part to cover the Demon ' s need to feed on those girls . The Concierge almost captured the Doctor in his time craft , but the Doctor managed to force his way out . ( AUDIO : " The Demon of Paris " ) The third object — a storybook with images of the Doctor and Mike Yates in it — drew them to a cave in eastern Europe , where the Demon had set himself up as an Ice Queen with a story teller , Albert Tiermann . Direct threats to Mike did not hold the Doctor , and again the Demon disappeared empty - handed . ( AUDIO : " A Shard of Ice " ) The Demon built a trap in New York City in 1976 . He had a meteorite land in Central Park and bestow super - powers to local resident Alice Trefusis . When the Doctor investigated the comic book cover showing the event , the Demon used a telepath debilitator to confuse him . Posing as ageing film star Mimsy Loyne , the Demon almost captured the Doctor , but was foiled when Alice broke up the chanting cultists necessary for the debilitator . In frustration , the Demon kidnapped the Doctor ' s companion , Fenella Wibbsey , outright . ( AUDIO : " Starfall " ) Sepulchre . Following the last item — a golden heart pendant — the Doctor went straight to Sepulchre . The Demon , no longer needing any disguises , sprang the trap on the Doctor . He revealed he was actually working for Mrs Wibbsey , or rather , the Hornet s that had regenerated inside of her . The Demon locked the Doctor in a sarcophagus , and started the process to extract all of knowledge of space and time from the Doctor ' s mind , using it to create the Atlas of All Time for the Hornets . A quick turnabout by Mike Yates set Mrs Wibbsey in the sarcophagus instead , quickly destroying the Hornets , the Atlas and Sepulchre . The Doctor , Mike , and Mrs Wibbsey escaped in one direction while the Demon escaped in another direction , free to roam the universe . ( AUDIO : " Sepulchre " )