At the heart of the sewers of Chex City lies a beast unlike any other. The Flemoidus Maximus. He's a match in power to the Flembrane, but don't think twice about him being any easier. Especially when you figure out there's actually two of them. Oh boy. He first appears at the end of Chex Quest 2. What a relief, until Chex Quest 3! He reappears in level E3M5!
He replaces the Baron of Hell from Doom.