Full name: Flat Girl Age: 16 Occupation: Worker Weapons: Hand to hand combat Era: 1-1001 Status: Dead Friends: Flat Boy and Flat citizens
Enemies: Flat Monster and servants.
The girl who is captured by the Monster as a trap for the Flat Boy so he can get captured and even killed so noone will ever escape and he'll have the whole Flat World all to himself. She is the secondary character.
Flat Girl is 16 years old, the same age as her male counterpart. She is freed out of her cell when the Flat Monster is slain and gives The Flat Boy a kiss in appreciation and eternal gratitude..
She is not seen until the death of Flat Monster.
Flat Girl manages to give to her bow aiding Flat Boy in destroying the Demonic figure when he resorts to to killing him.
- She has outlived her male counterpart Flat Boy, him living 999 years while she's lived exactly 1000 years, she probably died on the recreation of Flat World.
- She and Flat Monster use hand to hand combat.
- She is only mentioned after the death of the Flat Monster.
- It is not known how they all died; the planet probably blew up, and formed together bits and pieces such as rocks, gas and ice to create a new planet but this has not been confirmed.
- She is with Flat Boy in a wedding suit seen in 3D world.