Man, sometimes it is like folks working on this game focus so much on the narrow bits that they miss the big picture. This is one of those moments.
Dryads and nymphs are very close (being fey representations of various wild things), but they have dramatically different defining qualities -- big picture, they play very different roles.
Dryads are defined in my mind by their relationship with trees. This is subtle in their physical appearance -- green hair, dark woody skin, leaves and vines in place of clothes, etc. Their beauty (which doesn't have to be feminine in my mind -- no reason we can't have hawt dryad boys) is metaphor made literal: it is the beauty and desirability of the tree itself that is given form in a way that speaks to those who want it. When you use a Dryad in the game, you use it something like an NPC encounter: they have knowledge, perhaps treasure, and probably have problems helpful PC's can solve, and maybe if the party pisses it off something bad happens. It's like encountering a wild animal, or a vagabond: maybe it'll be OK, maybe it'll be a problem, but it reflects a world bigger than this particular encounter. It's a chance to reinforce your character archetype by imagining how they'd react to this creature, if they'd help or hurt or try to profit from it.
Nymphs are defined in my mind by their beauty. Again, in my mind, this doesn't have to be feminine (segsy nymph dudes should be a definite possibility!), but it is also metaphor made literal because nymphs represent wild places in general. It is the beauty and desirability of a place where no one has gone before (IYKWIMAITYD), the desirability of something no one else can understand, and that no one can ever truly understand (hence the blindness and death from beauty). When you use a nymph in D&D, you use it something like a "gotcha monster" -- a trap encounter. It's not something you're expected to really interact with very much, it's something you either suffer from, or not, and then the moment is over. Sometimes they can grow into NPC's, but they're more dangerous of the wilderness than fully-formed characters, typically. When they are NPC's, because of their nature, they're necessarily limited ones. Nymphs are dangerous -- not hostile, not aggressive, but just by what they are, risky to be around.
Beautiful things are not just beautiful things that are one-dimensional beautiful things. Beauty isn't necessarily a defining trait for the beautiful. I'm a straight man, so I know plenty of women I find immensely beautiful who aren't then
defined by that beauty. There's a lot more that my girlfriend offers.
With a nymph, for the purposes of artwork, it's probably OK to be defined visually by that beauty. I think the most accurate Nymph artwork would probably look more like amorphous blobs of light and shadow than any person. Like staring at the sun. Like the opposite of a Lovecraftian horror: all perfect angles and appealing symmetry.
With a dryad, beauty is there, but it's not what makes them unique or special. Yes, they're lovely in the way that all ineffible faerie magic things can be lovely, and it's important that they
are that, but they aren't defined by that. They're defined in D&D by trees, by wood, by leaves, by branches, by greens and browns and autumnal reds and golds and floral pinks and violets, by fruit (literal and metaphorical).
I'm not a fan of the monstrous dryad. Dryads and nymphs are not
hostile creatures. They're magical and mythical and metaphorical and beautiful, but they're not there to fight and die in 5 rounds. They're not going to come after the PC and attack them until their dead. They have other concerns. They don't need to look like they're going to get in a fight -- they probably AREN'T. Even a dryad who has to get hostile is going to get hostile by getting the trees and animals to kick your butt, without having to do much more than lift a magical finger.
naturally) or just consider them a "shapechanged succubus" which is more than adequate (they being demons of temptation, after all) is up to whatever you want.
