The 5 animals are not the only animals and the 5 are not all the original names. For example: The Cobra. But this just makes sense to call it a snake. So on with the information

There are 5 foundation animals that are recognized and taught. Those are “The Dragon”, “The Tiger”, “The Leopard”, “The Crane”, and “The Snake”. 
It is these 5 animals that embody important warrior virtues.

The Dragon – “Shen” is what it symbolizes and it does it oh so well. Shen means spirit. Dragon principles on the basic level are about “Riding the Wind” aka Flow. But in the advanced stages there are aspects of swaying, rising and sinking, floating, movements are soft and smooth yet it’s grip is fierce, it is the only animal that is a scavenger, meaning that it will use strikes from other animals to fill in opportunities, and it loves to keep it’s opponent off center/balance. 

The Tiger – The basic principles you learn about the Tiger’s strength and tenacity but the advanced tiger principles becomes even more interesting. You learn to use your body on your linear attacks and counter attacks, larger circles are used to maul your opponent, often times not caring about what you hit as each strike leads toward dominating your opponent. You learn about it’s fierce grip and the ability to tear, break, and paralyze the body. It uses gross movements while attached so throwing it’s opponent around is more efficient.

The Leopard – Starting principles of the Leopard are speed and power. But learn the advanced principles and you will learn about how the Leopard targets joints (weak areas of the body), how it uses not only it’s paw but it’s Leopard Claw. You move offline and attack or counter your opponent at an angle, most often using your forearms, elbows, and knees. One of the other interesting characteristics is that, similar to some dragon techniques, enjoys using opposition movements. That means it will get ahold of one part of you and then either get ahold of either another or some leverage and use the opponents natural tendency to move away against them. A great example of that would be if you had a person bent forward using a wrist lock and then you kicked them in the head. Their wrist breaks! Aka. being stuck between a rock and a hard place.

The Crane – A wonderful animal for sure. Hard to get a feel for the principles but not impossible. On the basic level you are looking at grace and balance. The advanced really take you to places that you would not have expected. Advanced principles include: keeping your opponent uprooted, using both the Yin and Yang striking (inward and outward wings), you learn to yield so that you have the option to allow your opponent to drive by or the opposite, you yield so you can snap back, like a bow string.

The Snake – This is not the easiest of animals and is not normally taught to beginner or intermediate student, but the beginning principles are flexibility and rhythmic endurance. As you get into the more advanced principles, you will learn about restricting, vice locking, advanced leg and foot use, hard and soft working together, and how to create a joint anywhere to get around your opponents guard.

Above is some information, but there are many other principles not listed and then there are the specialized animals within the main 5, like: The White Tiger, The Golden Leopard, The Black Crane, The Black Tiger, to name a few.

And of course there are the alternate styles which all have their principals. Eagle, Monkey, Bear, Boar, Rat, Hawk, Falcon, Heron, Panther, Dog, Phoenix, Cobra, Lion, Wolf, Asp, Spider, Scorpion, Lizard, Praying Mantis, Centipede, and many more.