A mystery that I asked about 12 years ago has just been solved. In the tilesets of the 1986 PC remake of Ultima 1 is a a strange tile that never appears in-game (see my U1 Fun page). Dr. Cat has now confirmed that it is in fact "Spuds McKenzie, from the popular Bud Light ads of the 1980s". I am also trying to reach the developer who likely created this tile, hoping to learn more about its story, but I'm glad this outstanding question has finally been answered. I've updated the U1 Fun page as a result.
In other news, I made some small updates to the Ultima Underworld 1 info pages: