As mentioned, Octaver allows for a semi-variable fuzz, as does the Harpeggiator algorithm. They are real nasty, reminding me of some of the Downward Spiral era NIN sounds.
You can also use the Bias Trem to create a somewhat gnarly overdrive by cranking up the gain/mix knob; you may want to reduce the overall output as well. It works alright running into a driven amp, or as an unusual texture.
Joe
