Wizenheimer

Wizenheimer is the main antagonist of Super Mario World episode Ghosts 'N' Rus. He is a Magikoopa, owner of a mansion in forest.

Ghost 'N' Rus
Mario, Luigi, Princess Toadstool and Yoshi first encounter Wizenheimer while searching the Enchanted Forest for Oogtar the Caveboy, who is missing. After Luigi bumps into him in the forest, the Koopa Wizard takes Mario, Luigi, and Toadstool prisoner and forces them into a nearby Warp Tube, threatening to blow the trio up with a Bob-omb if they don't obey. The Warp Tube leads to Wizenheimer's mansion, where he shackles his prisoners in the basement.

Wizenheimer later captures Oogtar by simply teleport him into the dungeon after the caveboy arrives at his door and demands the princess and Mario brothers. Wizenheimer is later found in the basement when Yoshi ventures through the house to save everyone and faces Yoshi. The Koopa Wizard tries to attack Yoshi, but Yoshi, under suggestion from Oogtar, eats his wand, spitting out a magic blast that frees his prisoners. Mario then jumps on Wizenheimer's head, sending him falling down the staircase.

Yoshi Shuffle
In the Italian dub, the Koopa Wizard who transforms Luigi into an egg is explicitly called Wizenheimer.

Trivia

 * A running gag in the episode involves Wizenheimer's name continuously being mispronounced by the other characters. Such names include: Wisenheimer, Wiseacre, Wizenmeanie, Wisecracker, Wizen-wise guy, Wisen-whatever, and Wisen-whatchamacallit.