This is Zorro and his son Bandit. With that mask and cap, Bandit is destined to follow in his father's footsteps. Animals with fur come in a wide variety of colors and combinations of colors. Sometimes the markings spark our pareidolia, the tendency to see familiar shapes where none is intended. For example, this cat has a monkey on his back. Just by color patterns, cats can have handlebar mustaches and wear pants. And many dogs and cats have heart-shaped markings that makes us love them even more. If you look hard enough, you can sometimes see letters or numbers in an animal's fur. This calico cat doesn't know it, but she has a perfect upvote on her butt.
Some markings aren't exactly unique, but they are worth noting. Cats sometimes have a color split right down the middle of the face, often with heterochromia to match- like getting two cats in one! You may occasionally see an animal with vitiligo, when patches of fur can lose their color, which can be strikingly beautiful.
(Image source: KeyzerSoze85)
Unique fur patterns aren't limited to cats and dogs. This goat is labeled as such with a picture of a goat in its side. There are birds, cows, sheep, and rabbits in the list, too. See 50 pictures of pets with unique fur patterns that will give you a smile at Bored Panda.