|Attack(s)||Projectile Orbs, Bubble Beam, Spinning Attack|
Asteroidean is a giant starfish miniboss in Okamiden. It is the manifestation of all the hate emanating from the souls of those lost at sea. It is described to be about the size of a boat. He is fought completely underwater, being found at the entrance waterway to Sage Shrine. Chibiterasu and Nanami must defeat him before they can pass further and enter the Shrine. The battle occurs in a 2D side scrolling form. During the battle Chibiterasu and Nanami cannot physically turn around to face the opposite direction, so to attack the Asteroidean with Weapons they must always be to its left.
It is very resistant to attack before its five arms are severed off. Chibiterasu must use his Weapons and Brush Techniques to attack the Asteroidean until one of its limps begins to glow red. This is a signal that it can be Power Slashed off. During this time, it can hurt Chibiterasu by quickly spinning into him and hitting him with its arms. During its spinning it is invincible to attack. However, it can be stopped by using Galestorm in the opposite direction to the spin. It will also shoot single red bubbles at Chibiterasu.
Although it is very vulnerable when it's arms are removed, it will become extremely vicious and its attacks will cause more damage and be more frequent. As well as its regular attacks, once its arms are removed, it will begin firing foam from its mouth. This is its strongest attack and will cause huge damage if Chibiterasu is hit by it. It will, however, glow blue before this attack and it can be avoided by swimming around the arena. Once it has been damaged enough after its arms have been cut off, it will turn into its third form, a purple starfish which is about the same size as its armless form. It cannot be hurt by brush techniques, only weapons.
 Bestiary Entry
"The resentment of all souls lost at sea manifested itself as this boat-sized starfish. Avoid the foam it spews from its mouth and its long arms to protect yourself from being dragged to the sea floor."
Its name comes from "Asteroidea", the class that Starfish belong to.