A ghost is the spirit of a deceased, who become attached to the vestigium of a certain area and can live off vestigia or magic.
An avenging spirit or ghost who returns from the dead for revenge. A “ghost vampire” who lives off the magical force of others.
Trolls usually want to live on riverbanks, preferably on places overshadowed by stone or brick. For instance Nathaniel, a troll who acts as a police informant, lives under the arches of Richmond Bridge, having moved there from Hungerford Bridge.
They are anti-life, or Tactus disvitae. Vampires feed off the magic potential, including the vestigia, of their surroundings and of living creatures.
As other vampires, jazz vampires live off energy. In this case the energy comes from jazz musicians.
Unicorns resemble horses, but have a long horn in their forehead.
In the park surrounding Skygarden Tower lived a wood nymph called Sky. She died when the trees in the park were cut down.
Several encounters with foxes or foxlike creatures hint that foxes somehow are connected with the demi-monde.
When Peter Grant first encountered a Genius loci, he asked Nightingale if it was a mermaid. His response: "That wasn't a mermaid", made Peter say: "So there are such things as mermaids". To this Nightingale only answered: "Focus, Peter, one thing at a time".