No body, just an eye and tentacles on the bottom of the eye.
The Siere was built in the shadow realm to watch over gaps that panthers could escape in. This was actually the first creature Zealot actually came up with rather then copying Pheonix. And Pheonix actually was impressed with these new creatures that he bought some himself to watch over areas in the demon lands that devil cats could escape through.
Hades never bought them.