Masters of "claw and paw" combat, John Bear and his brother Grudd are man-mountains with a vicious winning streak in the arena. Thanks to an addiction to RadAway, they are almost impervious to the arena's traps, and the siblings have developed an impressive plan of attack: Grudd holds back, scorching the escaping foe with flamer fire while John rips the victim apart with a deathclaw gauntlet.
During the Scourge, his other brother Greg was taken in by the Brotherhood. However, he and Grudd were left behind due to being "too wild and mean". 
"They're savage! They're brutal! They're here to keep this worker in his place -- the undefeated Bear Brothers! Let's find out if the newcomer can hold his own against real fighters! Release! Fight!" – Arena announcer
↑ DLC01Quest_DLC01AboutPitt2_0000B3FC_3: For example, they took one survivor, a kid the called "Kodiak". But they left his big brothers behind, because they were too wild and mean. But as it turns out, the Bear Brothers were some of my finest soldiers. At least, until they went up against you. (Ishmael Ashur)