PetPet

In a near-future society that claims to have gotten rid of all monstrous people, a creature emerges from a painting seventeen-year-old Jam's mother created, a hunter from another world seeking a real-life monster.
There are no monsters anymore. In the city of Lucille, Jam and her best friend, Redemption, have grown up with this lesson all their lives. Then Jam meets Pet, a creature made of horns and colors and claws, who emerges from one of her mother's paintings and a drop of Jam's blood. Pet has come to hunt a monster-- and the shadow of something grim lurks in Redemption's house. How do you save the world from monsters if no one will admit they exist?-- Adapted from book jacket.