The series follows the fortunes of Dexter, a young prince without a crown whose father, the old king, is dead. Soon after the king's death, the evil wizard Renvick stole the crown and proclaimed himself king. He ordered his servants to imprison Dexter for fear that he would get in his way. However, Dexter fled into the woods, where he was found by the good magician Phineas, who rescues him. Phineas lives with a young dragon called Lulu. When preparing a potion, Dexter unwittingly caused an explosion bringing to life three monsters endowed with magical powers – Winkle, Gump and Boo.