I have implemented Parton's remarkable Gorgona Chess and Gorgon Chess,
which introduce the 'Gorgona'. It moves like a queen, but cannot
capture. Instead it paralyzes any enemy piece within its range. While the
knight can avoid the gaze of the Gorgonia, it is the only piece able to
capture an enemy Gorgona. And, what do you know, it works. It is a very
curious variant.
http://hem.passagen.se/melki9/gorgonachess.htm
/Mats