Spider Demon (Son)

Spider Demon (Son) (also called Spider Demon "Brother" or "Ani") is a supporting antagonist in the Mount Natagumo Arc of Demon Slayer: Kimetsu no Yaiba.

He is a member of the Spider Family, a group of demons living on Mount Natagumo and posing as a dysfunctional "family" under the leadership of Rui (Lower Rank Five of the Twelve Kizuki), who acts as the youngest "brother" but is actually the most powerful.

Appearance: He has the body of a large spider (with eight legs, thorax, and abdomen) but a human-like head featuring pale white skin, red dot markings on the face, white hair similar to Rui's, and distinctive eyes with dark red sclera, blue irises, and black pupils.

Personality: Sadistic, cruel, and loyal to Rui's twisted family dynamic—he enjoys taunting and abusing others while fully embracing his role as the "eldest son."

Abilities: He possesses highly spider-like traits compared to the rest of his "family." His main power involves producing potent venom through his spider physiology, which can poison victims and gradually transform humans (including Demon Slayers) into mindless spider-like creatures with human heads, making them subservient to him. He can also create strong silk threads.

He fights Inosuke Hashibira during the arc and is eventually defeated and killed.