Who is Bunny Brown from Black No More and what is their importance?

Bunny Brown is described as a short and plump black man, who has been Max's friend since World War I when they served in France. In the novel's opening, he works as a teller in the Douglass Bank. After undergoing Crookman's treatment, however, he reappears in Atlanta where Matthew gives him a job as his assistant. Bunny is always supportive of his friend, and he even has the Givens' house burned down to help out Matthew.