What is a hyena?

the hyena lives in Africa and Asia. it is part cat part dog and it won't usually hunt its own food it eats remains of a lion or leopards meal.
Hyenas do hunt down most of their food, yes they still do scavenge on the side but most preds do. In fact lions steal the kills of hyenas a lot more then they do. which might be one reason most the time people find a group of hyenas standing around a lion eating is a good chance the lion had just chased them off of the kill beforehand.

Also they aren't exactly part cat part dog. Though they do have more dog like features, they're said to be closer related to felines, But they're even closer to mongooses and civets, but for the most part, they're their own species to a certain extent, There is four known breeds of hyena's today. The most known being the spotted hyena, followed by striped hyenas, then there is the brown hyena and aardwolf.
You can easily find plenty more info around the web, such as wiki for instance.
And here's another place http://www.smithsonianmag.com/science-nature/hyena.html
[a quote from their article]
" Spotted hyenas sometimes scavenge, but, contrary to popular belief, they kill 95 percent of their food. As hunters, alone or in groups, they equal leopards, cheetahs and lions. Yet the lion is considered noble, the cheetah graceful and the leopard courageous, while the hyena is seen as sneaky and vicious-a cringing scavenger, a graveyard lurker"
And another.

"The chimpanzee expert Jane Goodall, working in Tanzania's Ngorongoro Crater, expected to dislike spotted hyenas, but they soon won her over. "Hyenas are second only to chimpanzees in fascination," she wrote; "they are born clowns, highly individualistic." Wildlife biologist George Schaller, studying lions on the Serengeti in the 1960s, exploded another misperception by reporting that lions scavenged more kills from hyenas than vice versa."

And here's a blogpage from the Michigan State University [They have a research group for hyenas] http://msuhyenas.blogspot.com/
They are dog-like animals with a sloping body, as their front legs are longer than their hind legs. They have a short, sandy coat, covered with dark brown spots on the body and legs
a hiena is mamal that lives on the African saphari and in other places as well once thought to be in the dog famaly the hiena is acualy in the cat family
a hiena is a dog looking much like a grayhound but skinnier, it lives in hot countrys and is known for laughing insted of barking :)