Fuzz pedals that sounds like the Mountainking Megalith
 

I've been listening to some demos of the Mountainking Megalith and it's giving me GAS big time, although i'm not too keen on the size of the pedal or the price.

Are there any pedals out there that sound like a Megalith but smaller and/ or less expensive?

You can get some of the Megalith like sounds from MountainKing Heavy Machine. It is a cool pedal but it is not quite a Megalith.

I have no idea what the Megalith is based on (if anything) but I've played one once and I feel that I can get similar (not the same) tones buy using a boost into a muff based pedal.

To me the Heavy Machine and Megalith are different, but both are very good, intense, bass heavy fuzzes. If OP likes the Heavy Machine idea it's worth it to also consider the Huge Box II, same fuzz just a simpler tone section and a little cheaper.

Everything Alan makes are original circuits and point to point wired, not saying they aren't expensive but they aren't a rip-off either. They're all bigger than they need to be, and I've seen a few nice rehouse jobs to get them smaller but that would only add to your cost.