|“||Your body, I have copied... Your power, I have copied...||„|
|~ Dark Bowser to Bowser.|
Dark Bowser is the form the Dark Star took on when it absorbed Bowser's DNA while it was inside of him. When he got out of Bowser though he was incomplete as in he was missing legs. It was only when the Dark Bowser vacuumed up Dark Fawful Bug (the new form that Dark Fawful took on when he was defeated by Bowser) that he was able to become complete. He then busted through a throne and revealed a new area.
Bowser fought Dark Bowser on the very tip of Peach's Castle as the first phase of the final boss battle. Whenever Bowser got him down, Dark Fawful would heal Dark Bowser from the inside. Bowser would then get him to spit out Dark Fawful, who was merged with the Dark Star Core, who was then inhaled by Bowser for Mario and Luigi to fight. Once the Dark Star Core was destroyed, Dark Bowser was rendered unstable, allowing Bowser to finish him off with a Sliding Punch. He reverted back to the Dark Star, rose into the air, and was destroyed, restoring light to the Mushroom Kingdom.
- Dark Bowser is the 3rd final boss in the Mario & Luigi series that is a different form of Bowser, the first two being Bowletta and Shrowser, and the 4th and 5th being both Dreamy Bowser and Shiny RoboBowser. However, he is the only one who is never actually Bowser, because he only looks like Bowser, and is actually the Dark Star.
- His voice is a slowed-down version of Bowser.
- Dark Bowser is similar to the Fright Mask from Paper Mario and its sequel, only with yellow eyes and a darker palette.