This is a boutique pedal, and currently on sale at the dOpEfX website.
Its based on a Russian Muff I believe, but with a full tone stack (bass, mid, treble). This seemed like a good idea to me, since with my EHX Bass Muff I wanted more control over the EQ.
For a pedal with a picture of Satan being worshiped by a skeleton on the front it has remarkably little gain(!). My Bass Muff has more.
That however, is the only bad thing I can say about it. The tone is thick and alot sweeter than my EHX. The 3 band EQ is well designed and gives a wide range of sounds. And its very nicely put together.
For full-on doom metal I would say you'd need a boost in front of it. But anyway, this is a very good quality fuzz and at the sale price its currently at I must heartily recommend it.