Slipknot recorded two albums in 2008 – All Hope Is Gone, which we've all heard; and Look Outside Your Window featuring vocalist Corey Taylor, guitarist Jim Root, percussionist Shawn "Clown" Crahan, and DJ Sid Wilson. The album has been the subject of many rumors over the years, and is promised to come out at some point according to Clown.
Though if you ask Root, it would've already been out. Root joked (I think) in an interview with Metal Hammer that he keeps telling Clown he's gonna post Look Outside Your Window on YouTube one day, which is not an idea Clown likes.
"Man, I keep telling Clown that I'm just gonna throw it up on Youtube, then put a link to it on my Instagram or something," said Root. "He's like, 'Don't dude, just don't.'"
Root later noted that he doesn't really remember what the record sounds like, as it was recorded over a decade ago. "I don't even remember what any of that stuff sounds like, because it's been so long since we recorded it. I don't think I've listened to it in probably 10 years. Maybe I'll go find him after we are done talking, and I'll be like, 'Let's listen to Look Outside Your Window, and let's release it tonight…'"
Look Outside Your Window has been promised to fans since 2019, so who knows – maybe one day we'll get it, but we're also coming up on six years of "maybe." So don't hold your breath. I'd also wager that the longer Look Outside Your Window doesn't come out, the higher expectations get from fans until whatever it is won't be able to meet those expectations.