The world of The Simpsons is obviously packed with fictional pop-culture products, from Krusty Burger, to Malibu Stacy, to the McBain movie that works surprisingly well when edited together. And as far as we know, Nuts and Gum isn’t available in stores.

One thing that many fans likely assumed was just another invention of the show was Nelson Muntz’s disturbing wall poster. In Season Eight’s “Lisa’s Date with Density,” Lisa develops a crush on Nelson and ends up visiting his house after school. Along with two racist bumper stickers, his room is decorated with a poster depicting a mushroom cloud in the ocean, accompanied by the slogan “Nuke the Whales.”

When Lisa asks if Nelson actually believes in this grotesque statement, he simply shrugs his shoulders and says, “I don’t know, gotta nuke something.”

Well, it turns out that this terrible poster was, in fact,...