He is voiced by Ryuji Saikachi in the Japanese version of the anime and Scott McNeill in the English version.
Taigokumaru was the leader of a clan of bat demons and father to Tsukuyomaru, who fell in love with a human woman, Shizu, with whom he would later have a half-demon daughter named Shiori. The love he felt for Shizu estranged him from his Taigokumaru, as well as his choice to abandon the hereditary duty of guarding the barrier. This estrangement led Taigokumaru to kill his own son, but he did not kill Shizu when he realized she was pregnant with his grandchild, since he needed Shiori to be the next guardian of the barrier. He made a deal with the nearby village that if they gave his granddaughter to him, he would let the village be. After Shiori was born, the villagers ostracized her and eventually gave her to the demon, but Taigokumaru reneged on his part of the bargain and attack the village. Inuyasha then intervened, but could not harm Taigokumaru due to the barrier, but when Taigokumaru revealed in front of Shiori that he killed her father, she offered to let Inuyasha break the orb responsible for the barrier, allowing him to gain the Red Tessaiga. Even so, his spirit emerged from the orb and attacked Shiori, but he was killed when the spirit of his son intervened and defeated him permanently.
Taigokumaru was a rather cruel and ruthless daiyōkai who cared very little for others, even his own son. Taigokumaru admitted to slaying his own son Tsukuyomaru when he threatened to leave the bat demon tribe and abandon his post as guardian of the barrier. Like most demons in general, Taigokumaru felt great superiority to humans. Taigokumaru forced Shizu to give Shiori to him and he promised that he and his bat demons would no longer attack the village if she did so; he later went back on his promise and ruthlessly attacked the village, calling Shizu foolish for believing that he would keep a promise to a mere human. Taigokumaru also appeared to be rather intelligent as well, when he noticed that Inuyasha was a half-demon like Shiori, he quickly deduced that Inuyasha must have felt sympathy for her and was recalling his own situation. It was unknown if he actually cared for Shiori, as he mentioned that he actually valued her as compared to the villagers that ostracized Shiori and didn't hessitate to sacrifice her, though this was likely a facade as he saw Shiori as only source to maintain the bat barrier.