Burgerstein (known as The Great Sir Lord Willenby Huxley Shroomingmeyer III, Esquire, P.H.D. and Philanthropist Extraordinaire in the 2.0 version) is the fourth boss in A Koopa's Revenge II. He is fought at the final stage of World 4, the Jolly Toy Factory.
As the name suggests, Burgerstein is a humanoid being resembling Frankenstein's Monster, but made out of fast food. His head is a squared hamburger with eyes on the top bun and a pair of metal bolts sticking out of the sides, while his hands appear to be made out of fries. He wears a black suit and pants, although the latter are only visible for a moment in his introductory cutscene.
In the 2.0 version of AKR2, Shroomingmeyer is a large humanoid created when Mario enchants a Golden Mushroom with his magic. His body resembles a humanoid mushroom stalk, his arms and legs are formed from twisted brown mycellia, and his head is a brown spotted mushroom cap squashed into a roughly cylindrical shape by a huge golden crown around it. Two red gems set in the front of the crown act as eyes, and small mycellia form eyebrows and a mustache to complete the monster's face.
At the start of the battle, Burgerstein falls through the floor at the center of the room, leaving his torso exposed. The rest of the floor is made of conveyor belts constantly moving towards the boss, potentially damaging the player if they don't keep away from him.
Burgerstein attacks by throwing a fireball from his hand or slamming the ground, causing debris to fall on random parts of the belts. Eventually, he'll toss a Slider onto the same belt as the player; stomp on the foe to render it inert, then toss it at Burgerstein's head to damage him.
It takes five hits to defeat Burgerstein; after each hit, his "debris rain" attack will cause one more piece of junk to fall every time he uses it. In later phases, the safest way to avoid the debris is to jump on the boss's head as he slams the ground; he won't take damage, but the player will never be hit by falling debris if they're directly above him. After taking three hits, he adds a new attack to his repertoire; after charging up for a moment, he'll shoot five fireballs in a spread formation around him.
In the 2.0 version, The Great Sir Lord Willenby Huxley Shroomingmeyer III, Esquire, P.H.D. and Philanthropist Extraordinaire fights exactly like Burgerstein. However, his Sliders are replaced by evil Super Mushrooms; when stomped on, their eyes become spirals and the skull-shaped marking on their caps becomes a round spot.
- The Great Sir Lord Willenby Huxley Shroomingmeyer III, Esquire, P.H.D. and Philanthropist Extraordinaire has the longest name of any character in the "A Koopa's Revenge" series.