"Hm... I don't think cathorse is something you become, perse. As far as I know, I was born this way. Always have been, always will be cathorse.
As for what parts of me are catlike? The teeth yeah, obviously. I do feel my fur is a lot softer, like that of a cat's. I suppose my tail could be reminiscent of classical unicorns, but lots of ponies have called it very cat-like as well. Helps me keep balance when I lurk on tree branches. Also, I don't know if you've noticed the slit pupils?
And yeah, of course I like black too! I just like the contrast of a bright color too."