You cannot imagine how Jungiangly dumbfounded I was this morning to see that TDG link speculating that "monsters" such as Nessie might be ghosts. I had started to write a blog entry along those lines yesterday but then got sidetracked and did not complete it. Once you have digested as many of the better TV ghost hunting shows as I have the idea of these fortean creatures being ghosts makes all the sense in the world. Spirits often shape shift like crazy when they are particularly energetic and mischievous. The demonic ones relish morphing into various monstrosities, and if the ghosts of people and creatures such as dogs, cats, horses, whatever can rise from the dead and visually manifest then the idea of a creature separated only by vastly more distant time seems quite possible especially given that one of the first average human illusions to fall by the wayside when ghost hunting is that time carries any weight at all. The "distant" past means absolutely nothing in terms of the ability to manifest in the here and now. Energy apparently resides dormant in matter indefinitely and can be reawakened at any "time."
It would be interesting though to correlate monster sightings with concurrent changes in the local environment. I am thinking especially of radio towers, radar towers and such having been erected in areas where the sightings are condensing. There is a lot of evidence that high powered EMF's can pry loose "ghosts" from their mooring in matter and make them dance before your eyes especially if the area in question also contains large rock formations either subsurface or above, and water is another big factor. Ghosts take advantage of water energy to manifest. That may be why so many of the fortean creatures are water creatures.