MXR M 236 Super Badass Variac Fuzz

It is a band of gypsies fuzz with a bias and a tone control. Very dynamic. The sound is thick at lower to unity volumes, and the tone control cannot bring back the lost high frequencies. In short it may sound a bit woofy.
The unit has tons of output, so it is very easy to overdrive the amp by using the unit volume knob alone. But YMMV depending on the amp headroom.
The unit got brighter at very high volumes, and given the huge amount of output it is not practical to leave the volume of the pedal close to max and use the volume control of your guitar, because the unit has too much output for a good control on the guitar. Less is more in this case.
Keep in mind that "band of gypsies" fuzz is an approximation of what the pedal was done by MXR, since the pedal Jimmy used has never been recovered from theft/loss.
To conclude, it is a very versatile unit, with many possibilities but sound is always subjective.