You'll deliver babies, save individual members of endangered species, cure sick animals, and develop relationships with creatures that most people don't even know exist—or are way too afraid to go anywhere near. It's all glorious.
You're also a liaison between man and beast. Every time you teach a new person to respect and appreciate wildlife, you're making the world a better place.
Also, you might have to save someone who falls into the lion's den or gets too close to the polar bears. That'll score some serious glory points for you. Not to mention a giant "Thank You" card from the hapless victim.