Demion el Pulpo

You work in a zoo of endangered monstrous species. Demion becomes a semi-human Octopus, one of the last males of his species, and refuses to mate with any female offered to him. Now he also refuses to eat. It's incredibly violent and you are a species specialist hired to 'tame' it. Or: you are the next best playback option (not copied content but I hope it doesn't bother me by using the base story)