Hello
This is mostly a prefrence because it is a texture. Although I can see why you would think that the ingame and real life cat is not identical. The reason is that the available pixels on the cat is such low in quanitity that it becomes almost impossible to have all the features from the real deal.
Hello
I could not reproduce this in any of the 3 latest versions in neither of the 3 dimensions. It is very likely that you did what zhangchenglig14259 stated. I also believe that the only mobs with the reinforcement mechanic are Zombies and their variants (Husks, Drowned, and Zombified Piglins)