Barry is a super mutant stationed in the Necropolis watershed in Fallout.
Barry is the brother of Harry. It seems that familial ties run deeper than just the name and serving in the same squad, as Barry is mentally challenged almost as much as Harry. That is still enough to keep tabs on Set and Necropolis.
Though he was vanquished by the Vault Dweller, the Vault Dweller's memoirs state that he burned Ian to death with his flamer.
Barry appears only in Fallout.