A sprite of Ohsat preparing to attack
Ohsat is a boss in the game Ristar.
Ohsat is a purple and blue hammerhead (shark) who invaded the Water Control Room of Planet Undertow and is causing the waters to raise and lower at random times.
Ohsat is the boss of Planet Undertow, he is the second boss encountered.
He will begin by appearing next to you. This is a good chance to strike him. He will also slam into the walls in the background, causing rocks to fall into the water where Ristar is. He will also attack with a stream of Baracuda, being another great chance to attack. He will also drop Jellyfish Mines into the arena.
After four strikes, he will flop around on the ground, now drained of all water. You must strike him once more to stuff him into a hole, defeating him.