The discussion surrounding the depiction of gnolls in TSR era Dungeons & Dragons has been quite lively, both in the comments and in emails sent to me privately. Another commenter pointed me toward an even more obscure gnoll illustration.
This full-page piece originally appeared in 1981's
The Sinister Secret of Saltmarsh
and is by Stephen D. Sullivan. There are two gnolls depicted above, both in the center of the illustration. The first is standing upright, grappling with a sword-wielding fighter. The other is on the ground,
biting at the fighter's leg. It's an odd thing to depict, since I don't recall gnoll's having a bite attack in any TSR edition of
D&D, but, if I am mistaken about this, I am certain one of you will correct me.
In any case, Sullivan's gnolls teeter on the line between looking properly hyena-like and more canine/lupine. Personally, I prefer it when monsters are
their own thing, not just real-world animals with a few bits added or subtracted, so I don't want gnolls to look
exactly like hyenas. At the same time, I also don't want them to be
dog or wolf-men either (though, interestingly,
The Keep on the Borderlands) does, on its rumor table, describe them as "big dog-men," so what do I know?