Primus and TOOL are both bands with extremely dedicated fanbases, and there's certainly a lot of crossover between the two camps. For fans who love the weirder, proggier, more humorously twisted side of metal, then there's no two better groups to get into. Therefore, it was a pretty big fucking deal when TOOL drummer Danny Carey performed with Primus at Chicago's Riot Fest in 2014, especially when the group busted into a cover of TOOL's "Ænema," the title track (spelled slightly differently) from their 1996 masterpiece Ænima.
As you can see in video of the set, the guys used the TOOL song as an interlude before seamlessly transitioning into one of Primus' most beloved hits, "My Name is Mud." From the sound of the crowd around the camera person, it seems like some fans didn't recognize or know what to make of the "Ænema" part, but the room went buckwild when Les Claypool started banging out the "Mud" bassline. For the real ones who can appreciate this glorious medley, watch it happen above and below via YouTube