This is a sweet seven months old kitten .. He was afraid of chickens at the first seen, but now it is just used to them. But sheep are mammals, and if I make him a lamb animal, maybe a little - going to sleep next to each other to keep warm, keep him company at night and hear "? or should we be afraid, and the sheep will scare him?
Pet cats adapt to other pet animals quite fast, I have a cat and a golden retriever (A big lamb actually, if you say that) while the cat was scared of goldie initially, she got along quite well in 3 days.. If sheep is not aggressive, I think both will be fine.
It doesn't really matter if your cat is sweet or not. Cat have instincts that have them react to things in certain ways.
I don't think that cat will get scared. I had a cat in past and she knows very well that how to defend herself. So stop worrying about that.