If making beats and creating music were like cooking (they kind of are, right?), percussion would be like the spices and herbs. You don't have to have percussion in your music, but if you do, it can really set you apart from everyone else and make your music that much better.
Organic Percussion comes with 35 real percussion samples. It includes bongos, congas, djembe, shaker, tambourines, and more. These are high quality samples and if you're trying to grow your sample library, I think they will be a perfect fit.