Urriak Uruk
Gaming is fun, and fun is for everyone
Are all gnolls created from hyenas eating demon flesh in 5e? I thought that was just how the original gnolls were created.
Either way, it doesn’t much matter to me whether they reproduce sexually or not. The issue is that evil is a part of their nature rather than something they do, and can theoretically choose not to do.
I disagree with his assessment. Their origin story is one of natural beings (beasts) uplifted by consuming the flesh of fiends. That’s not how fiends are created in D&D canon. Classifying them as humanoids was a correct choice, and I believe Crawford is trying to rationalize his desire for gnolls to be always evil, just as Tolkien struggled to rationalize his desire for orcs to be always evil.
The label isn’t the issue. The issue is the nature of the being the label describes. Fiends’ (and all outsiders’) nature is defined by their alignment, whereas humanoids’ alignments are defined by their nature. If an evil human stops being evil they become a neutral or good human. If a devil stops being evil it becomes a different type of outsider. Gnolls function more like the former, or at least I think they should. A gnoll that becomes good shouldn’t become an angel or whatever, that would be silly.
I'll have to check my Volo's Guide to Monsters, but my memory was that yes new gnolls are made exclusively by the hyenas eating flesh, that are following the gnoll pack. I know that isn't consistent with earlier editions, and that gnolls used to have even gender, but I don't believe in 5E that has remained. I definitely don't remember anything mentioned about gender in Volo's.
Anyway, my opinion is that in 5E gnolls may technically have choice, but because of their fiendish origins they are always going to pick from a narrow range of violent options. So I don't really think they're truly sapient creatures at all.
UPDATE: I have checked my copy of Volo's, and it is pretty unequivocal that gnolls are made by hyenas consuming corpses killed by other gnolls or Yeenoghu the Demon Lord. I encourage you to read it, as I find it hard to spin that this 5E canon for gnolls is anything close to redeemable, or even a creature capable of non-evil choice.
As for the humanoid label, I'll add it is by far the least well-defined category of monster (monstrosity is pretty vague too). For example, werewolves are humanoids when 5E lore is pretty clear that the curse of lycanthropy tilts people towards evil (though weirdly werebears are normally good, so it's weird). Deep Scions are humanoids, and I find it hard to imagine people who make deals with evil underwater monsters as good. Heck, Nagpas are humanoids!
Anyway, it seems to be that mechanically humanoid is meant to be something used for mechanics (spells, feats etc) and is not tied well to sapience, freedom of choice, or alignments.