Who is the narrator in the book, The Unnamable?

The narrator of The Unnamable lacks all characteristics of a human being - he has no name, gender, no past, or body. He exists in a vast indeterminate space whose parameters he cannot figure out, and it does not seem that he can move either. All he can do is speak - incessantly, to no end. He says that he is under the control of "his delegates," or "masters," who are forcing him to speak and who try to convince him that he exists, but it is unclear whether they themselves are "real"; one of them, Mahood, tells the narrator stories as if they happened as a part of his past life, but he also seems to be just another voice in the narrator's abyss. Nothing "happens" to the narrator in the conventional sense: he appears to be a manifestation of a brain-in-a-vat scenario, a recreation of a consciousness wrought by epistemological uncertainties and ontological anxieties.