Daniel Dumile—better known by his rap alias MF DOOM—turns 44 years old today. Running down his list of achievements feels never-ending, with collaborative projects alongside MadlibDanger MouseBishop Nehru, and Jneiro Jarel displaying his diverse catalog, as well as solo albums like Operation: Doomsday​ and Mm.. Food solidifying his presence as a pillar of the underground rap scene. 

It's amazing to think that he's had such a prolific career in the shadows, so to speak, as he's taken on a mysterious approach that switches up with each and every rap alias: MF DOOM, Zev Love X (with KMD), Viktor Vaughn, King Geedorah, Metal Fingers, or simply the "Super Villain."

If you've followed DOOM's enigmatic career, you should be well aware that interviews with the rapper are few and far between, and also vary depending on which alias he's portraying. So we did some digging to get a closer look at the man behind the Metal Face mask. From his first rapper name, to the origins of his mask, sneaker collaborations, and his surprising friendship with one of the biggest rappers alive, there are a lot of gems here for the taking. Here are 20 Things You Didn't Know About MF DOOM.