Gnollrunner:

Yes, it's about hyena-people -- specifically, the spotted hyena-people, Homo crocuta.  I've had the rare privilege to know some of them, so I wrote a book called The Gnoll Credo.  It's the first book (and still the only book) about gnolls.

If you want to know more about all the "other stuff" that's here, read my FAQ.  The connection between gnolls and the "other stuff" will be obvious once you've read the Credo. 

JS

Gnollrunner:

TGC isn't about diet.  It's Gryka's biography, or what I know of it.  Any philosophy it contains is my effort to come to terms with what I learned from her.

Keep in mind that the world of TGC is not the D&D world: it contains no magic, and its creatures must survive on their own merits.  As such, its gnolls aren't the gratuitously bloodthirsty demon-worshippers depicted in D&D manuals.  They're much more like spotted hyenas, in both behavior and social organization. 

Here's a brief history of the concept of the gnoll (originally spelled "gnole").

JS

Gnollrunner:

I've indeed seen that article, but not until after I'd written the first draft.  There are similarities -- but there are many more differences, because the gnolls I know are much closer to Crocuta crocuta than to the D&D conception of a creature with demonic blood and its consequent internal conflicts.  

In summary, if you're looking for a book that explores the world of D&D gnolls, you'll be disappointed.  (Though that could be an excellent book, it's not the one I wrote.)  I think my publisher's description summarizes TGC well:

"Against all advice, an unsuspecting ethnologist (Aidan O’Rourke) travels to the frontier of human civilization to study gnolls—a tall, fearsome race of feral hyena-people best known for uncompromising savagery in battle and a propensity to eat their victims. Expecting yet another simple and brutal primitive tribe, he finds instead a complex society of matriarchal, pack-hunting predators with a stark and beautifully bleak philosophy of existence.

Gryka, the gnolls’ charismatic liaison to humans, quickly draws Aidan out of his scholarly detachment, and into her violent yet compelling life. And as Aidan’s extraordinary adventures with a fierce, joyous, and hilariously blunt carnivore transform into a complex and intense relationship, Aidan becomes entangled in the gnolls’ transition from their purely animal past to a difficult and uncertain future among humans who would gladly kill them all if they could—culminating in a violent confrontation between the two worlds."

Further reading:

http://www.gnolls.org/forums/talk/a-hyena-question/

http://www.gnolls.org/forums/talk/bestiary/

JS

Gnollrunner:

I'm jealous!  Though I've seen live spotted hyenas, I've never been to Africa to see them in the wild.  But even from the captive examples and the videos, it's clear that they're extremely intelligent, inquisitive animals.  At the wildlife park, most of the carnivores just slept the whole day...but the spotted hyenas were up and about, checking out all the visitors (paying particular attention to the children, which they clearly understood would be slower and easier to catch), begging for (and getting) neck-scratches from the keepers, and generally being interested in anyone who paid attention to them.

The striped hyena video you're thinking of can be found here.  And I've read several accounts of people who keep spotted hyenas as pets: apparently they're also quite tameable, though due to their inquisitive/destructive nature and great strength, nearly impossible to keep.

JS

Paleobird:

It's tough being a cheetah: something like 90% of their kills are appropriated in part or in whole by other predators, usually lions or hyenas (though sometimes leopards).

Ironically, the larger the predator, the more often it engages in "aggressive scavenging" (i.e. stealing kills) vs. hunting.  If you're a lion, it's much easier to chase away a cheetah than it is to catch a Thompson's gazelle yourself!  And, in fact, lions hunt perhaps 40% of their food (the rest is scavenged, usually from hyenas).  Hyenas hunt 60-90%, depending on region: in the Ngorongoro Crater, lions are essentially parasitic on hyenas!  Cheetahs and wild dogs hunt basically 100% of their own game, because they can't chase off anyone else (except, perhaps, the odd caracal).

JS

Paleobird:

No, I didn't know that about elephants in the Ngorongoro.  (I've never been to sub-Saharan Africa.)

"I was told by my guide that the lady lions find this shade very attractive.  Probably should fact check things that guides say."

Ha!  I've seen a "Barbary lion" (which may or may not actually be descended from them) in a wildlife preserve with a very dark mane...except the shading is more black, not brownish.  The mane also extended all the way under the belly, not just around the neck.  I think it looks quite nice...but I'm neither female nor a lion.

JS