That's a name I made up. No one seems to know the what/why of this thing. Thanks to the marks, we do know the who/where for once. This weighs 28 lbs., I got it at a gun show maybe 25 years ago.
I've fired it once. We put a couple of ounces of FG black powder down the hole in the top and fired it. I can't really describe the sound except maybe something like a sizeable rocket taking off from the top of your head. A neighbor ran outside his house and yelled "is anybody hurt, call 911!"
I should mention that it has a sizeable cavity inside as a chamber, and the exit at the top is designed a bit like a rocket nozzle. They've left quite a bit of metal around the chamber on all sides, it appears.
So what is this thing, you tell me, I've given up.