Why are MUD decks called MUD?
Generally, quite a few older deck names aren't really meaningful &mdash; they're a weird in-joke or just a random word someone pulled out of nowhere &mdash; and that tradition has been carried forward to the modern day in Legacy/Vintage as well. This is how you get the likes of Fruity Pebbles, Cephalid Breakfast, Team America (which is BUG, not red-white-blue), and Tinfins.

Sometimes there's a story behind it, but that story amounts to "I liked this reference" or "We had waffles at this restaurant the day before." About the most interesting story you're going to get from these is Boat Brew (created for a cruise; achieved massive hype quickly; lots of people today joke that it was an awful pile of a deck).

I've seen various backronyms for MUD, but really what you need to know is:


MUD plays gobs of artifacts
MUD decks are usually defined by Metalworker
Artifacts (used to) have brown frames


The rest seems to be speculation and folk tales.