Phantoms and Monsters: Pulse of the Paranormal

Lon Strickler has a good post about the high strangeness factor that surrounds Sasquatch. I like the question he muses upon here:

Phantoms and Monsters: Pulse of the Paranormal: Is it possible that ghostly creatures or cryptids may roam our planet? Could these be residual energies of previous living beasts, that manifest and present the effect of non-terrestrial or interdimensional beings. On the other hand, is there a chance that we are chasing corporeal entities that slip in and out of our plane of existence? (Strickler, Phantoms and Monsters)

Critics of the non-flesh and blood idea ask this how it is that a creature can leave footprints, for example, but not be otherwise present? Well, ghosts do such things; leave behind physical effects (scratches, moving items, sounds, EVPS, etc.) even while not being fully flesh and blood. If ghosts, spirits and other non-human entities can pop in and out of our reality, why can't Sasquatch? I'm not suggesting Bigfoot is a "ghost", rather, that Sasquatch might share some of the same mechanisms ghosts and spirits exhibit.