Basilisk

A basilisk is a reptilian creature which possesses a gaze that enables them to turn any fleshy creature to stone -- a gaze which extends into the Astral and Ethereal Planes. They are usually dull brown in color, with a yellowish underbelly. Its eyes glow pale green.

While it has strong, toothy jaws, the basilisk's major weapon is its gaze. However, if its gaze is reflected, and it sees its own eyes, it will become petrified itself, but this requires light at least equal to bright torchlight and a good, smooth reflector. In the Astral Plane its gaze kills; in the Ethereal Plane it turns victims into ethereal stone. These will only be seen by those in the Ethereal plane or who can see ethereal objects.

Some basilisks, called greater basilisks, also have poisonous claws and foul breath.

Note: The basilisk originally appeared in this form in the 2nd Edition Monstrous Manual for the AD&D game from TSR. Their use here is for the purposes of providing context for the campaign only.