In about 303 AD Armenia became the first Christian state. So of course, the Christians wiped the old gods off the map which means little is known of the pre-Christian mythology of Armenia.
Still there’s some cool stuff out there. A Vishap is a shape-shifting dragon that seemed to hang out around water. Vishap stones are large stones found around the country with serpents or fish heads carved into them…perhaps warning signs of the Vishaps that lived near by.