Do you mean it needs the [NIGHT_CREATURE_HUNTER] tag, or do you mean it just won't work in a civ creature because it has to be a lone stalker type thing?
So they'll shear there own beards, rather than a shearer carting them off to the farmer's workshop? And will they trade thread and cloth made of their own hair and webbing?
I had wondered how luck of the draw would affect pegacorns(maybe I should call them royal or thoroughbred, so I can be consistent across the species), but really, if they're too rare, it does become sort of inevitable people will slaughter migrants to get more of them. After all, sieges are partially population based. What I'll do is I'll use obnoxiously big numbers for population ratios, so pegacorns and equivalents are 200 out of 6000 as standard or something, and people can easily tweak the pegacorn numbers to suit their taste. In fact, I'll probably be rolling out the duplicate caste system for forcing genetic diversity soon(after evil and cave ponies), so I'll probably roll the two out together, so the numbers are easier to manage.
You'll notice that each caste of ponies and zebras tends to have one set of colours, because I've defined them all individually, so all female ibis zebras in a world will be striped carmine and puce with black wings, for example, but all male ibises will be black and cream with pearl wings, because the colour genetics is linked to that specific caste because I've defined them separately. What I'm going to do to force diversity is have a [CASTE:FEMALE_IBIS01], [CASTE:FEMALE_IBIS02] and so on, and give each a duplicate of the descriptor guff at the end of the file, so the basic castes will look more diverse because they're being tracked as half a dozen separate strains each under the hood. They'll still be randomised, but we'll be getting half a dozen random results per caste instead of just the one, which is better than crowds of five or six samefriends in the show. I know it looks horrible and high maintenance, that's why I've been putting it off. Any better ideas would be greatly appreciated.