To use Rockjaw, you can first stretch him to unleash his stretch attack when playing battles with other Heroes of Goo Jit Zu Stretch Strikers. Squeeze and stretch his body gently to discover his unique filling. When you're done playing, keep him in a dry place away from sharp objects to avoid any damage. This toy is suitable for kids aged 4 and up, so adult supervision might be needed for younger kids. Don't pull too hard on his body to prevent it from tearing.