Lore the Fifth City Wiki will not tell you

Eaten was the runt of his litter; he was thus consumed, as owl-chicks do to their runts when the clutch begins to starve. On a probably related note, Eaten is also the one Master most consistently referred to with binary pronouns. From these factors, it can be inferred that Mr. Eaten almost certainly canonically lacks a particular half of the Dual Nature. That is probably worth keeping in mind for any batkissers who may wish to selfship themselves with him (whether with the fragmented revenant that now remains or with what he once was in his prime).