Gnolls
Gnolls are a problematic race. Originally created as a tougher monster to kill than orcs (http://en.wikipedia.org/wiki/Gnoll) their fluff included the phrase "hyena-like."
Then some enterprising individual looked up hyenas (http://en.wikipedia.org/wiki/Hyena). Madness ensued. The lack of sexual dimorphism, the female pseduo-penis and anal glands led to a furry-based explosion of gnoll perversion.
Yet gnolls were not cast to the curb. They remain a challenge for low to mid-level players for GMs who dance around the inherent strangeness of a "hyena-like" race.
Unified Setting Description
This much has been agreed. Gnolls are matriarchal. Female gnolls do not have a pseudo-penis.