Plumbers Academy Mario loses his golden plunger after a battle with Koopa. He tells Princess & Toad that this was a special plunger because it was given to him by the President of the United States. In pre-show flashback mode, Mario tells how he and Luigi became plumbers, and how they had to put up with their overly strict boss, Sgt. Kooperman (who sounds a lot like Koopa). Kooperman ended up flunking the Marios, who soon found themselves facing their biggest plumbing challenge ever.