The gaze attack has a fairly low accuracy: there is a 75% chance that it will miss plus another 66% if you are either invisible or displaced. If you are reflecting and the gaze would have connected, then it will kill the gazer.
Although the catoblepas is not randomly generated, it is a valid polymorphable form, so it is perfectly possible for a chameleon or intelligent monster with a wand of polymorph or polymorph trap to suddenly turn into a catoblepas. It is also possible to self polymorph into a catoblepas, but beware of monsters with reflection, as a reflected gaze of death will kill you even if you have reflection yourself.
Strangely, the catoblepas is a unique monster, yet also genocidable. This is mostly irrelevant, but if you wish for the corpse of one in wizard mode, it will be described as "The catoblepas' corpse" rather than "A catoblepas corpse."
The catoblepas is a legendary creature first appearing in the writings of Roman historian and naturalist Pliny the Elder. It was described as a large quadruped from Ethiopia, with a very heavy head held in a downwards position; the name comes from the Greek for "to look downwards". It was said to possess a gaze or breath capable of turning people to stone or simply killing them.
Like the unicorn, the catoblepas is thought to be based on fanciful descriptions of real animals, in particular gnus or buffalo.