Lizard Baby (2004)

Original title: 日野日出志の怪奇劇場 わたしの赤ちゃん

Horror screenwriter, Umeki, has writer's block. He goes with his pregnant wife, Akiko, to a check-up and is struck with an incredible idea - a horror story about a woman who gives birth to a reptile! Despite his wife's disgust, Umeki goes ahead with the screenplay, which the critics love. But the horrible prophecy fulfills itself, as his wife gives birth to a freak of nature. His baby is born half human, half lizard! The reptilian baby slithers on the floor, leaving a wet trail of slime behind [it]. To his horror, his wife, Akiko, holds it lovingly in her arms. His movie has become a mirror image of his own life as Umeki slips slowly into madness.