When teenager Lucas (voice of Phillip Vasquez) discovers that he is not human as he always thought, his world is turned upside down as he must adapt to being a monster. Not only is Lucas troubled by the fact that his first transformation occurred at school but also that his father had kept him in the dark about his true nature. His frustrations lead Lucas to leave home in pursuit of the fabled Monster Island with the hope of learning the truth about his heritage. His journey brings him into contact with several weird and wonderful individuals, not all of whom have good intentions.
