Slipknot has clearly replaced percussionist Chris Fehn ever since his departure over a lawsuit with the band, and we still don't know who the hell the new guy is. Slipknot refuses to tell anyone their identity either, so everyone has been referring to him as some variation of "Tortilla Man" due to their mask looking like a tortilla.
The band has now incorporated Tortilla Man's identity mystery as a part of their percussion art as you can see in the below photo, and it's a pretty fantastically placed Easter Egg for fans to have found. The PRP reports the new percussionist may be Zach Hill (Death Grips, Team Sleep), though as usual this should be treated as a rumor and nothing more. So for now they're just Tortilla Man.
Slipknot will release We Are Not Your Kind on August 9.