Dark Star X9 is a antagonist who had a role at Super Mario 64 Bloopers: The Videogame, appearing as the former secondary antagonist of said game, before his defeat; after being defeated, Bowser gets the role instead.
Dark Star X9 was the final boss of SMG3's Tower. If the player hasn't collected all Power Stars, he's even the "final boss". In the story mode, Dark Star X9 is always fought with Shy Guy, no matters which character the Player was controlling before the battle. Also, Dark Star X9's battle is always 2D, meaning Shy Guy can only go left and right.
Dark Star X9's battle has two phases:
In the first phase, Dark Star X9 is fought in the throne room. Dark Star X9's main attack is to fly in random directions and trying to ram into Shy Guy. After this attack, Dark Star X9 will flee the throne room. Later he can been flying behind one of the windows in the room. After a short period of time, he will bash trough the window. If he hits Shy Guy he'll deal massive damage. Glass cullet will aso be flung in random directions, which deal massive damage as well. Dark Star X9 will then try to ram in Shy Guy again. This are his only attacks in the first phase.
In the second phase of the battle, Dark Star X9 and Shy Guy will be flying in a zone in the air (still in 2D). Shy Guy must shoot Toast at Dark Star X9 to damage him while avoiding it's ramming attacks. After a while Dark Star X9 will get bat wings. He'll then dispatch his wings to launch an enormous Flare Attack (as seen on the image on the upper right). After this attack, the Dark Star gets it's wings back and continues fighting. The Dark Star X9 will now shoot yellow stars at Shy Guy. After shooting enough Toast at him, Shy Guy will fly away. Dark Star X9 flips over and lands on his back, floundring with his wings as it implodes.
- A much stronger version of him (Dark Star X17) is fought in The TRUE Arena.