Gwen Stefani posted an Instagram story this weekend of her middle son Zuma enjoying a birthday party with a magical Harry Potter theme. The event, held at their L.A. home, included life-sized cutouts of Potter, Severus Snape and Draco Malfoy, as well as flags and balloons representing the four Hogwarts houses. The food included an owl made out of pineapple and melons and a three-tiered cake topped with a Sorting Hat. E! reports that Zuma turns 9 later this month.