He does not sleep, but he dreams. Motionless for several hundred years. Caked in dust he lies, naked on the floor, his skin the temperature of stone, his nearly-sightless half-closed eyes like rocks, his great heart beating quarter-of-the hour. He does not sleep; he does not think, he waits and waking dreams the distant sounds and slow procession of scent. The taste of motionless air. Something has happened, far above, a pressure easing. Something vast has shifted in the earth. Maybe something else will happen now. Maybe soon.   His bones are cartilage, like a shark’s. He could never walk. He crawls, if he has the space, on deeply calloused forearms and knees, often pausing to listen and sniff the air. If he could stand, he would be about 18 to 20 feet tall but slender and starved. As he crawls, his eyes will be about five feet off the ground, level with yours.   Cartilage deforms more than bone so he can, with time, work its way through spaces that in human scale would be little bigger than a letterbox mouth, about the size (relatively) of an A4 book. There is no part of the Observatory he cannot access. If he attempts to squeeze into a small passage, he fills it. The players may see, ahead of them, a pale gigantic hand reaching towards them, clutching at the rock. Behind it an arm, a shoulder and then a gawping face filling the width of the passageway, rolling opalescent eyes under half-closed lids, a mouth like the boot of an economical car, the huge teeth in it grating as the jaw deforms. His only option is to crush you against the wall with his outstretched hand, or grab you and squeeze you to death, then to slither forward and scoop you up in its mouth. He will eat you, chewing well, equipment and all, to get you out of the way.   He could come into your house through the front door. He could slowly squeeze his body up your stairs, filling the stairwell with his flesh, then send one questing hand through your bedroom door. He could squeeze his head into your room and look at you.   He is strong His bones will not leverage force; to kill, he must twist off limbs and bite with his great teeth. He climbs well, oozing and creeping up the rock with every point of his flexible body in contact. He is silent and highly intelligent.   If you could speak to him after he ate, you might possibly be able to negotiate, though there is nothing he wants except to eat again.