He’s so large that his outstretched wings can cover the entire sky. Fortunately, he seems to live at the other end of the Solar System and doesn’t come by too often.
ALKHA often chases after the sun and moon, swallowing them as a tasty treat. Which invariably leads to hiccups. All he can do is regurgitate them back up again.
According to the Buryat people, he takes the form of a fearsome head without limbs or body. In other words, a head. This presents a problem when he tries to swallow as there is nowhere for those tasty morsels to go. They pop straight out again.
If you’re ever worried about eclipses, the best thing to do is shout, throw stones at the sky and try to scare him away.