Rent The Good Son (1993)

Evil resides in an unexpected place in this gripping, suspense-filled drama. Macaulay Culkin stars as Henry, an angelic-looking boy who seems loving and loyal to his parents, sister and friends. Only his cousin Mark (Elijah Wood) sees what lurks behind Henry's smile -secret thoughts and love of deadly games. But when Mark tries to warn Henry's family, they won't believe him, leaving the terrified youngster alone to battle his jealous, menacing cousin.