Shadow Queen

Shadow Queen is an ancient demon and the main antagonist who serves as the final boss of Paper Mario: The Thousand-Year Door.

Prior to the start of the game, she destroyed an ancient civilization and began a conquest on the entire world with the aid of numerous monsters that she created and the Crystal Stars. In the end her plans were ruined and she was sealed away by four heroes within the Thousand Year Door. Even though she was sealed away, her followers vowed to bring her back into the world and did so around the time when the seal on the door was weakened enough. Her followers tricked others into opening The Thousand Year Door, allowing the queen to be free from her prison, which brought darkness to the whole world.

Summoning the Queen, Grodus presented her with Peach whom she then possessed, who then became "Shadow Peach", her summoning engulfing the world in darkness. Grodus, thinking the Queen was under his control because he revived her, ordered her to destroy Mario. The Queen, insulted by Grodus thinking her to be a slave, blew apart his robotic body. The Shadow Sirens then appeared, and Beldam explained to the Shadow Queen they created the myth of an ancient treasure and tricked Grodus into reviving her, and the Shadow Queen thanked them for work. The Shadow Queen then sees Mario, and offers him a choice of being her servant, which he of course refuses (the player can choose yes, but it will result in an instant Game over). She then attacked Mario, and while the fight was not too hard at first, the Shadow Queen eventually became invincible. None of Mario's party attacks were able to do any damage and all Mario could do to survive was to wait until the crystal stars came out in response to the evil in the area.