Slaughter Metal
It is the extreme hardcore version of Death Metal, which is the extreme hardcore version of Heavy Metal, or Metal, which is the extreme hardcore version of rock, which is the best genre of music, including all varying types of Metal.
I can't name any right now but they would have to be more metalish and screamo than Slipknot, which would be very...creepy... There is a posibility that there are no Slaughter Metal bands on the planet...but i have my hopes.......