Fake Bowser is a green version of Bowser. When Fake Bowser was born, only Bowser knew who his parents were. 500 years later, after Fake Bowser gave up looking for his parents, he decided to live with Bowser. He is also has a crown on his head instead of hair.
He danced every day and every night. Sometimes Laa-Laa would join him, but it was really just an assassination attempt. Fake Bowser once danced so hard, that he turned evil, and wanted to work with Bowser to kill Mario