The Catalinbread Perseus is a sub-octave fuzz pedal that delivers fuzz and one or two octaves down. Run the Catalinbread Perseus with just fuzz, just octave, or blend them both and try to outdo the Perseus nebula for the lowest note in the universe.
The Boss OC-3 SUPER Octave borrows sounds from its predecessor the OC-2, but unlike any other octave it is the world's first compact pedal with true polyphonic octave effects. For the coolest octave around try the Boss OC-3 SUPER Octave.
The Boss MO-2 Multi Overtone enhances your guitar's overtones. The MO-2 boosts the natural second and third generation frequencies to create 3 different harmonic profiles, with or without a substantial layer of pitch-shifting modulation.
The Blackout Effectors Crystal Dagger is an effect like you've never heard. Putting together an octave fuzz with a ring-mod/phase circuit produces some interesting results and the Blackout Effectors Crystal Dagger does just that.