The Megalopros is a pterodactyl. He appears in Darius Force.
Megalopros, perhaps in part due to the funny scrolling of the level, uses the whole screen to attack, and uses it well. In general, it's both clockwise-anticlockwise motion. Any kind of emission from can hurt, so stay away. When he first bursts on to the screen, try and stay in the lower-right corner. Once he settles on the left side, he launches missiles from thorax and abdomen, and fires a straight laser from somewhere in-between. Fancy, but not too bad. As he moves diagonally downwards, he fires three-bullet arcs and his wings fire three straight lasers (like a WWII fighter plane, actually). Nasty.
Megalopros then moves northeast (watch out for the wingtip boosters) and repeats the wing cannon thing, but backwards. Watch out for the mines he lobs at you too. When he moves a bit lower, his abdomen fires more missiles at you! He then moves a bit left and opens his beak to fire a nasty, lightning-ish beam. The cycle repeats from here, with the most important thing to watch out for being maneuvering space! An easy but long way to deal with him is to float around him and merely sticking to bombing him from the edges.