Shrieker

Shrieker is a Hollow that is a serial killer prolific is also major antagonist of Bleach.

Before Becoming Hollow
Before becoming Hollow, he was a serial killer who killer 7 people or 8, her consistently bragged about escaping the police. He would one day go to his last victim as alive a woman and her son who was called Yuichi Shibata, he killed his mother, and his mother, and in an accident caused Yuichi Shibata, he killed his mother, and in an accident caused Yuichi both Shrieker and Shibata died. After that, Shrieker became a Hollow, he held a grudge for the boy, but instead he manipulated Shibata into winning more souls by promising that he would bring his mother, even though he knew he had no ability to do so after some time two Shinigami tried to help Yuichi.

Battle against Ichigo
During this time, Ichigo and Rukia set out to help him. However when Shrieker appears and attacks everyone in that place, the Hollow fights Rukia and Sado, he soon attacks everyone in that place, the Hollow fights Rukia and Sado, he soon realizes that Rukia is a Shinigami after she kido him, then Rukia asks why he is after the boy, seen Shrieker devoured two Shinigamis trying to help him Yuichi. Shrieker attacks Rukia and asks her why she didn't leave her Gigai, but he is interrupted by Sado who attacks him, but Shrieker realizes he can hear him but not see him.

He then feigns his defeat, and then attacks them both Rukia and Sado, he throws his leech at the two, which injures Rukia, and when Sado prepares to retaliate. However, Shrieker reveals that he has Yuichi for him, making Sado retreat and still. Then Shrieker begins to chase after Rukia.