Fukegao

Fukegao (フケガオ Fukegao) was a genius scientist who developed the Biceps Brachii King steroid, which turned his brother Marugori into a mutated giant. He was accidentally killed by Marugori when the latter mistook him for Saitama.

Appearance
Fukegao is a slim and pale man, with wrinkles. He has thin black hair that is parted in the middle, draped along the sides of his long face. He dresses in typical scientist clothes, a long white lab coat and a regular back shirt.

Personality
Fukegao has a great hunger for power and the ambition to conquer the world. He is shown to be delusional, sadistic, arrogant; going so far as to promote himself as the most intelligent person on the planet. However, his arrogance is somewhat well-founded as he proves that he is incredibly intelligent, able to create the superhuman drug that made Biceps Brachii King. During the brothers' rampage, Fukegao continuously screamed orders at his younger brother to destroy more towns and kill more people to prove the power of his steroid.

On the other hand, it is implied that he cares for his younger brother greatly and is even shown to be considerate. It was shown that Marugori was the one who dreamed to have the strongest body, and implied that the Fukegao's superhuman drug was specially made for him. In the anime, Fukegao tells Marugori that he went so far as to add strawberry flavoring to help the drug go down more easily. Ultimately, Fukegao seems to strive for him and his brother to be the most powerful duo in the world. More than anything, Fukegao seems to disapprove of the power of the drug, not the strength itself, as he is never shown to have consider taking the drug himself.

Saitama Introduction Arc
Having spent considerable time making a steroid drug, he finally succeeded in completing the ultimate steroid, the Biceps Brachii King. In his lab, he hands it to his brother and tells him to drink it. Marugori does so and the drug takes effect, causing his muscles to burst out of his clothes and his body expanding to the size of a skyscraper. Fukegao is amazed by this and yells out that the Brain and Brawn Brothers will conquer the world. However, the rumble of the wrecked lab falls on top of Fukegao and he gets stuck. He calls out to his brother, who releases him and puts him on his giant shoulder. Fukegao again declares that together, they have the greatest intellectual and physical power in the whole world. They march on towards D-City where Marugori, upon entering, destroys several buildings with a mere swing of his fist. Fukegao is astounded by his brother's strength and is excited by the death of so many people at once. He motivates his brother to wreck the next town as well.

At B-City, he cheers his brother on, but lets out a surprised scream when he notices Saitama on his brother's other shoulder. He orders his brother to kill him, but Marugori mistakes which shoulder Saitama is on and accidentally slaps the shoulder where Fukegao is sitting, killing him.

Intelligence
Genius Intellect: Fukegao was an individual of exceptional intelligence. He was responsible for creating the Biceps Brachii King drug.