What is the one word for eyed monster?

There isn't a single word in English that perfectly captures the meaning of "eyed monster." However, depending on the context, you could use words like:

* Cyclops: A one-eyed giant in Greek mythology.

* Gorgon: A monster with snakes for hair and a deadly stare.

* Behemoth: A monstrous creature mentioned in the Bible.

* Chimera: A mythical creature composed of parts from different animals.

Ultimately, the best word depends on the specific characteristics and imagery you want to evoke.