The Black Dobers (ブラックドーベル, Brakku Dōberu) were an infamous gang of ghouls that operated out of the 20th ward roughly a decade prior to the series. They were identified by their black clothing and black masks that resembled a Doberman.
Their leader was Kaya Irimi, prior to the group being disbanded when she joined Yoshimura at Anteiku. The gang was responsible for killing numerous associates and teachers of Investigator Chuu Hachikawa, who was left heavily scarred and made wiping them out his personal mission.
The members reunited and donned their old masks one final time during the raid on Anteiku. Many were seriously wounded or killed during the course of the battle, with the survivors fleeing underground. These fleeing ghouls were ambushed by Squad 0's leader, Kishou Arima, and wiped out. Their leader Kaya Irimi would be rescued by Ken Kaneki and go on to fight the CCG again in the Rushima Landing Operation and join the organization Goat.