On certain autumn nights when moonlight mingles with fog and residual magic or spirit energy a Haunlupe egg can form. Haunlupe eggs spend most of their time being incorporeal, only gaining a tangible presence in this world in the hours before hatching.
The Haunlupe is a strictly nocturnal species whose presence is associated with hauntings. However Haunlupes are not the cause of hauntings instead they seem to be drawn to haunted areas. Given time any area that exhibits signs of a haunting will attract at least one Haunlupe. When a Haunlupe takes residence in a haunted area or building paranormal activity will increase. This effect seems to have diminishing returns as the presences of additional Haunlupes past the first do not measurably increase paranormal activity. It's been speculated that the presence of a Haunlupe provides more energy for spirits to manifest. Unfortunately this theory has proven difficult to test as Haunlupes are as difficult to capture as the spirits themselves.
Haunlupes appear to be made primarily out of ectoplasm and energy. They spend most of their time in an ethereal form that can pass through solid matter. However they can briefly manifest physically and have been seen interacting with objects and living beings.