Dark Coronatus is the boss of zones G and I from Darius Twin. It is shaped after a seahorse.
Dark Coronatus cycles between three attacks: a triple energy ball-arc from his head, spawning smaller versions of itself from his midsection which chase the player but can be destroyed, and a four-bullet arc shot after it stretches it's body. It's weak point on the midsection. Both variations of the boss play the exactly same.