Mr. Dumass
You might think it's actually pronounced Doo-mas, but the actor's name is actually pronounced Stu Williams. This was one of the most popular Superbowl commercials of the 1990s, and for good reason. A&W Rootbeer piled a lot of cash into this ad spot.
Here's the Kicker
Williams actually has extremely fond memories of playing this character. He got paid $50,000, which was a lot of money in the 90s. Recently he started his own personal YouTube channel and was able to upload this commercial and monetize it under his contract with A&W.