Dr. Arewo Stein is a character in the Super Mario series. He first appeared in the Japan-exclusive GameBoy game Kaeru no Tame ni Kane wa Naru. Wario encounters him a lot in Golden Pyramid in Wario Land 4. He is an elderly man with a large head, glasses, mustache, and beard. His name is a pun on 'o shitai'. He also appeared in the comic Super Mario Kun.