Not to be confused with the location Princess Peach's Castle.
Super Peach's Castle is a boss that appears in Mario & Luigi: Bowser's Inside Story. Super Peach's Castle was powered up by Fawful after seeing Bowser getting closer. The Castle crushes Bowser forcing Mario and Luigi to head into the Rump Command and turn him giant. After a long battle, Bowser defeats Super Peach's Castle and it reverts back to it's normal, yet now damaged, form.
Super Peach's Castle is similar in appearance to the actual castle except it now has a mouth, arms, and legs. Since it was powered up by Fawful, it also has swirly, red eyes.
In battle, Super Peach Castle has a wide variety of attacks. One of it's main attacks involves it simply charging at Bowser. It may also launch missiles and Mechafawfuls. It's main and deadly attack involves a black hole that can do multiple damage the longer the victim is trapped in it.
Timing is the key to winning in this fight, especially when it gets to the black hole battle phase. Bowser must attack carefully when the time is right to deal major damage.
- This is the final giant boss fight in the game.