Mad Scienstein

Arewo Shitain-hakase (meaning "Dr. Arewo Shitain") is a character who Wario encounters on multiple occasions while exploring the Golden Pyramid in Wario Land 4. He appears as a comical, elderly man with a large head, glasses, a mustache, and a beard. He is about 90 years old.

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. He heard the rumors of the Golden Pyramid and set off on his own expedition.

During the game, Wario can usually find the researcher 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 pick him up again in his original location. The researcher can sometimes also be found outside of bonus rooms, on the level select 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 appears as an obstacle in the The Wario Hop at the Mini-Game Shop, and is 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 implies that he reads pornography magazines, or masturbates while on his breaks.

Origin
While his first and only appearance in a Wario Land series game was in Wario Land 4, Arewo Shitain-hakase's character actually originated from Kaeru no Tame ni Kane wa Naru (カエルの為に鐘は鳴る, meaning For the Frog the Bell Tolls), a Game Boy game that was released exclusively in Japan. 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.