Phantasmagoria

Charles Dickens refered to a Gelth-possessed corpse as phantasmagoria. (TV: The Unquiet Dead)

Emily Holroyd recalled that the Torchwood Institute was created to combat the threat posed by the Doctor and other phantasmagoria. Jack Harkness clarified that the Doctor was not a threat and was infact "the one who'll save you from your phantasmahoojits." (TV: Fragments)