Princess Fiona is a fictional character from the animated film series Shrek. She is introduced as a beautiful princess who is initially trapped in a tower, guarded by a dragon. Fiona is known for her strong personality and independence, often challenging traditional fairy tale stereotypes. Throughout the series, it is revealed that Fiona has a unique secret: she transforms into an ogre at night due to a curse. This transformation plays a significant role in her character development and her relationship with Shrek, the titular character. Fiona ultimately embraces her true self and finds happiness in her unconventional love story.