喰う : to eat, to bite, to tease, to make fun of, to encroach on, to consume, to receive something (usu. an unfavorable event), to have sexual relations with a woman (esp. for the first time)

She seems to be doing most of those things, so. Translation unknown.

Maybe that was the artist intention? Anyway I feel "get eaten" would work better here, as in onis eat naughty kids/little boys (they do?)

Perhaps the innuendo could be preserved slightly with scare quotes.

she's a demon not goo