Mad Scienstein

Mad Scienstein, originally known in Japan as Arewo Shitain-hakase (meaning "Dr. Arewo Shitain"), and sometimes referred to simply as the Mad Scientist, the professor, or the doc, is a recurring supporting character who appears throughout numerous Nintendo games. He has filled a multitude of different roles and professions; including a scientist, researcher, robotics engineer and archaeologist. Mad Scienstein is a comical, elderly man with a large head, glasses, a mustache, and a beard. Despite being around 90 years of age, he demonstrates strong sexual interests.

Mad Scienstein first appeared in the Japan-exclusive game  under the name of Arewo Shitain-hakase, where he acts as a researcher who provides assistance to the player in providing useful items. After an absence, he reappears in Wario Land 3, being referred to as Mad Scienstein. Here, he appears as an occasional entity who creates and throws invisibility potions. In Dr. Mario 64, he is Rudy's main minion, who assists Rudy in stealing Megavitamins, prompting the player to pursue him throughout the game. He has most recently appeared as an archaeologist, known again as Arewo Shitain-hakase, conducting research within the Golden Pyramid in Wario Land 4.

Origin
Mad Scienstein's character originated from  (カエルの為に鐘は鳴る, meaning The Frog For Whom the Bell Tolls ), a Game Boy game that was released exclusively in Japan in 1992. In said game, he is known as Arewo Shitain-hakase, and is a member of the supporting cast surrounding the adventure of the Prince of Sablé. Arewo Shitain works as a researcher for an institute on Nantendou Island, providing the protagonist with helpful items such as gloves that increase strength, or a device that can control mammoths. He also appears in the final battle of the game, riding a robot of his own creation, the Tokyo Comic Show Z, which assists in defeating the final boss. Arewo Shitain is said to be a gourmet, and he frowns upon the thought of sharing his food. He is especially stingy when sushi is involved.

Wario Land 3
Arewo Shitain-hakase makes his first appearance within the Mario franchise in Wario Land 3, but with a redesigned appearance and a new name, Mad Scienstein. Here, he appears in a few levels throughout the game, starting with The Vast Plain. He carries many bottles of disappearing potions, which turns Wario invisible, allowing him to pass through Seeing-eye doors. While the rest of the enemies in the game are actually townsfolk cursed by Rudy, Mad Scienstein appears to still be human. However, his large bone-shaped head is replaced by a mechanical glass-domed helmet. Unlike most enemies in the game, Mad Scienstein makes no effort to hinder Wario's progress, and it is suggested by the official English website that he is trying to help Wario.

His name comes from "mad scientist" and "stein," a Germanic word and name suffix meaning "stone" that is commonly associated with scientists due to famous physicist Albert Einstein and the fictional.

Wario Land 4
Mad Scienstein appears in Wario Land 4 as an archaeologist, returning to his original appearance and name of Arewo Shitain-hakase, who came to conduct his own expedition of an ancient pyramid. He is first seen in the game's opening sequence, where a picture of him can be seen in the newspaper reporting the pyramid's discovery. In an official bio, he is stated to be a robot engineer and an Honors Professor at the Masakāchotto University Engineering Department.

During the game, Wario can usually encounter Arewo Shitain-hakase within the various pink areas inside the levels, where he can be found pacing with a magnifying glass. Wario can interact with Arewo Shitain in the same way as most other enemies: he can be stunned, picked up, and thrown to break blocks or hit switches that are out of reach. This is commonly required to solve a puzzle in the rooms to reach a Diamond. Arewo Shitain has a unique sound clip (a loud exclamation of "Oww!") that is heard whenever Wario harms him. Unlike most enemies however, none of Wario's attacks actually defeat Arewo Shitain. If he ends up falling in water, he dons scuba gear and swims along the bottom.

Arewo Shitain-hakase also appears as an obstacle in the beginning of the minigame The Wario Hop, where he is seen eating an onigiri, as well as various places on the game's main map. He also has various in-game idle animations, including one which depicts him playing with a Game Boy Advance. After Wario defeats the Golden Diva, ruler of the pyramid, Arewo Shitain falls from the ceiling after the pyramid begins to collapse. He is later seen trying to escape the pyramid alongside Wario and the black cat. While panicking, Arewo Shitain-hakase jumps on Wario in order to safely exit first. This is the final time that Arewo Shitain-hakase is seen in the game.

An interview with Arewo Shitain-hakase's character on the Wario Land 4 official Japanese gamepage confirms that he occasionally plays games to take a break from research. The same interview also suggests that he reads adult magazines and performs other activities while on his breaks that he cannot discuss with young boys.

Dr. Mario 64
In Dr. Mario 64, Mad Scienstein once again serves as a minion to Rudy, assisting in his plan to steal the Megavitamins from Dr. Mario after Wario made an attempt to steal them in order to become a doctor himself. Both Dr. Mario and Wario chase Mad Scienstein throughout the land, facing various foes from Wario Land 3. In Dr. Mario's ending, he cures Rudy to Mad Scienstein's joy, whilst in Wario's ending, Mad Scienstein steals the Megavitamins from Wario leading to the latter pursuing him in an apparently never-ending chase.

Dr. Mario 64 is also the first and only game where Mad Scienstein is playable. Mad Scienstein is slightly stockier compared to his appearance in Wario Land 3, and wears a metallic helmet in this game as well.

Super Mario-Kun
Arewo Shitain-hakase appears in volume 28 of Super Mario-Kun.

Wario Land 4 Shogakukan game guide (Japanese) (page #3)
"Robot engineering authority, Honors Professor [at the] Masakachotto University Engineering Department. [He] heard the rumours of the Golden Pyramid [and] set off on his own expedition. His age is about 90 years old."

Nintendo Power Advance issue #3, Wario Land 4 guide (page #54)
"To get the diamond, you have to employ the good doctor's help."

Faux character interview on the official Wario Land 4 webpage (Japan)
"Oh! My name is Professor Shitain! I also appeared in Wario Land 3! So of course you know me well! What? You never heard of me? Well, listen carefully. I came to this pyramid because I’m an archaeologist. As you pointed out, I do show up in Wario Land 4 to play games from time to time. Sometimes, I need to take a break from my research. Forgive me. Actually, I do some other things during my breaks, but it’s not appropriate for young boys... so have your mother explain to you someday!"

"It’s not easy to say out loud... I looked at something for adults. Even though I looked behind me to make sure no one was looking, it seems someone found out. I guess I’m a man after all!"