Brad could just be a generic name for him, as the Browncoat Zombie is considered to be the most generic zombie. However, "Brad" could also come from "Browncoat" itself
Just Brad is one of the most unique Battle Leaders due to the fact that he is an extremely buffed Browncoat. Getting hit by his attacks is almost guaranteed to be fatal, as he's able to deal 250 damage with his melee alone. Thankfully, unlike normal Browncoats, he'll never throw rocks at you, so taking him down should be easy as long as you keep your distance from him. Using Chomper is strongly discouraged as you won't be able to swallow him with the Burrow ability, and close quarters combat is impossible because of his powerful melee attack.