Slipknot have released a surprise new single - and teased their new album will be ''one of the darkest chapter's'' in the band's history.

The heavy metal outfit have given their supporters - known as Maggots - a taste of things to come ahead of their hotly-anticipated sixth studio album by dropping new thrash track 'All Out Life' as a Halloween (31.10.18) treat - and frontman Corey Taylor says the new record is ''fierce as hell''.

He said: ''The album is underway, and it's going to be one of the darkest chapters in Slipknot's history.

''It's that good. It's complicated, it's dark, it's heavy, it's heavy, it's melodic, it's fierce, it's angry and it's raw as hell. It's going to be talking about a lot of things that people are going to need in their life.

''It kind of had a cross between the first album and 'Iowa'. I keep telling people that this is what the kids from Iowa would have made if they'd matured. It's a step from that.''

Corey admitted the band's hard-hitting new track will get supporters in the mood for the upcoming album - a follow up to 2014's '.5: The Gray Chapter' - and he credited his fellow 'Wait and Bleed' hitmakers for penning ''some of the most incredible music'' he has ever heard.

Speaking to Zane Lowe on Apple's Beats 1, he added: ''Everybody talks about toxic masculinity and toxic fandom these days, but for me it's more about this toxic idea that unless something came out ten minutes ago then it's not any good - and that bothers me.

''I love new music, but at the same time don't turn your back on the music that's been. It's a rallying cry for everyone and saying, 'You know what? Let's not talk about old, let's not talk about new, let's talk about what is. Let's talk about what's good and what's real and get behind that.'

''Obviously I've been doing my thing, but [the band] just got together and started writing some of the most incredible music that I've ever heard. It was so good and so inspiring to me, that I just sat right down and wrote basically everything that I was feeling.''

The masked metal group have been working on their new album for the past two years, and Shawn 'Clown' Crahan has teased fans to expect numerous concepts on the record.

He said in a statement: ''Right now is a very exciting time for Slipknot. We've been working on new music for the last two years, and 'All Out Life,' the song and the video, is just one of many concepts in the works.

''It's a fitting taste to get you to the next thing. Get ready for what's to come.''

Corey recently claimed the group have written their ''heaviest song'' to date for their new album.

He said: ''At a time when most bands are slowing down, I think we've written our heaviest song - one of them anyway - on this new album.

''It's going to be f***ing crazy. People are going to s**t their pants when they hear it.

''It's also us at our most ambitious, our most experimental, also us doing what we f***ing do best which is basically when everybody thinks they've got us figured out, we just smack them in the face with everything we've got.''