'An alien survivor from a prehistoric saucer crash? An unfortunate time traveler from the future? A tradesman from a parallel universe? A hitherto undiscovered species? Or a mere freak deformity of a human being? Nobody knows for sure, but no matter the explanation, the Sealand Skull has potential to change the view of the world we live in.'
If you look at the big eye sockets, it seems to be the skull of a "Grey" alien.
It clearly seems to be a non human skull and more informed inspection eliminates a terran genesis unless that changes under further investigation. If it has been outright faked then it will not survive a DNA analysis.