The pegasus brings you to a castle in the sky. Surely THIS must be the location of the butt.
Behold! A dragon! It must have known about your quest to view the butt. She can see you, and she isn't happy.
Aha, a small butt shaped tomato! This must be a message from the butt that you are on the right track. Perhaps if you follow the tomato vines you will find ...