Who is The Bay from The Infernal Desire Machines of Doctor Hoffman: A Novel and what is their importance?

The Bay is the centaur who appears to be in charge. When Desiderio and Albertina happen on the centaurs, it is the Bay who investigates their legs and sexual organs, the Bay who appears to instruct the men of the village to rape Albertina, and the Bay who takes responsibility for Desiderio and Albertina by allowing them to live in his stable. From the Bay, Desiderio learns about the religion of the centaurs and the reasons for many of their actions. In fact, when the centaurs decides how to incorporate Desiderio and Albertina into their religion, it is the Bay who appears to lead the movement.