Mad Scienstein

Arewo Shitain-hakase (meaning "Dr. Arewo Shitain"), previously known as Mad Scienstein and sometimes referred to simply as doc, is a scientist, researcher and a recurring supporting character who appears throughout numerous Nintendo games, having filled a multitude of different roles. Arewo Shitain-hakase is a comical, elderly man with a large head, glasses, a mustache, and a beard. He is about 90 years old.

Arewo Shitain-hakase first appeared in the Japan-exclusive game Kaeru no Tame ni Kane wa Naru, 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 supports the game's antagonist Rudy the Clown, and creates potions which have an effect on Wario and the gameplay. He fills a similar role in Dr. Mario 64, where he assists Rudy the Clown in stealing Megavitamins, and the player must pursue him throughout the game. He has most recently appeared as an archaeologist, now known as Arewo Shitain-hakase, conducting research within the Golden Pyramid in Wario Land 4.

Origin
Arewo Shitain-hakase's character originated from Kaeru no Tame ni Kane wa Naru (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, Arewo Shitain 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
Mad Scienstein makes his first appearance within the Mario franchise in Wario Land 3. Here, he is a scientist and an assistant to Rudy the Clown, appearing in various levels throughout the game. He carries many bottles of disappearing potions, which turns Wario invisible, allowing him to pass through usually protected gates. While the rest of the enemies in the game are actually townsfolk cursed by Rudy the Clown, Mad Scienstein seems to be a minion of his, as he doesn't appear to be transformed in any way.

His name comes from "mad scientist" and "Einstein" or "Frankenstein".

Dr. Mario 64
In Dr. Mario 64, Mad Scienstein once again serves as a minion to Rudy the Clown, 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. Dr. Mario 64 is also the first and only game where Mad Scienstein is playable.

Wario Land 4
Arewo Shitain-hakase makes his first appearance in this game during the opening sequence, albeit not in person. A photo of him is shown in the newspaper that reports the discovery of an ancient pyramid. He is a robot engineer and an Honors Professor at the Masakāchotto (meaning 'Thatcantberightareyousure' while looking like Massachusetts) University Engineering Department.

During the game, Wario can usually find Arewo Shitain-hakase within the various bonus rooms inside the levels. Wario can interact with Arewo Shitain like he does with 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 Puzzle Rooms. Arewo Shitain has a unique sound clip (a loud exclamation of "Oww!") that plays whenever Wario harms him. Unlike most enemies however, none of Wario's attacks are actually lethal to Arewo Shitain. If he ends up falling in water, he will don scuba gear and swim along the bottom where the player can no longer interact with him. Therefore, Wario must leave the room and come back in order to interact with him again. The researcher can sometimes also be found outside of bonus rooms, on the game's main map screen. After Wario defeats the Golden Diva, Arewo Shitain can be seen escaping the collapsing pyramid alongside Wario and Princess Shokora, where he jumps on Wario in order to safely exit first.

Arewo Shitain-hakase also appears as an obstacle in the beginning of the minigame The Wario Hop, seen eating a rice ball. He also has various in-game idle animations, including one which depicts him playing with a Game Boy Advance. An interview with Arewo Shitain-hakase's character on the Wario Land 4 official Japanese gamepage confirms that he occassionally plays games to take a break from research. The same interview also suggests that he reads pornography magazines, or masturbates while on his breaks.

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