Annabeth Chase is a fictional character in Rick Riordan's Percy Jackson and the Olympians series. She is a demigod, meaning she is half-mortal and half god. Her father is the mortal Frederick Chase and her mother is Athena, the goddess of wisdom. She first appears in the first novel of the series, The Lightning Thief. Throughout the series she becomes close friends with Percy Jackson, later becoming his main love interest and girlfriend.