The alpha nigger in a group of tough-looking, hostile, or loudmouthed niggers. The nigger in the group with the loudest voice, or the one that the others seem to defer to (out of fear).
We were walking down the street when we saw a group of 8 or 10 black males in front of a liquor store talking and yelling in a hostile manner among themselves. Suddenly one of them in the loudest voice of all, starts yelling to tell the others where they should go next. Luckily we were walking on the opposite side of the street from these low-lifes, when my girlfriend, referring to loudest guy, turned to me and said, "Hey, check out Chimpus Maximus over there!"