The first part of the song is what I'm talking about, the heavy riff and such.

Anyways, the guitar tone is so fat on that part, what kind of pedals/effects would I need to get that sound? A good example is the guitar behind the lines, "Spitting out pieces of broken lung!" and the riff right after that.

I'm just asking because the sound is so odd, that I couldn't tell what was used for it myself, I think it might actually be some sort of keyboard behind it or something.