In a backstage photo shared on Kelly Osbourne‘s Instagram Story, Slipknot‘s mystery member may have been shown unmasked. The post has since hit the 24-hour expiration window and is no longer visible on Osbourne’s Instagram, but a screenshot was captured by The PRP and can be seen further down this page. In the photo, toddler Sidney, the son of Osbourne and Slipknot’s Sid Wilson, is seen looking closely at Corey Taylor‘s mask. The singer is hunched over, his face mostly smeared in black face paint which gives off a haunting, sunken look behind the openings of the mask. In the background, anothe…