Poor little Xoco. She has learned the hard way the perils of poking your nose (or in this case, your whole head) in where it doesn't belong.
I don't know exactly where she poked it, but this is what she looked like when I discovered her. Notice how one horn points one way and the other horn points another? She stuck her head in somewhere, got it caught, and in struggling to free herself has uprooted her horn halfway out of her head. Yeeowch!
With Ken's help, I caught her, pushed the horn back into place as best I could---it actually POPPED back into her skull!!!---and sprayed some insect repellent for wounds on it, to prevent fly strike. The last thing she needs is maggots in her skull!
She will most likely be fine, although the horn may never grow in quite the right direction again. She was one I was planning to keep anyway, so at least I don't have to wonder if the cosmetic issue will affect her sales value.