There's actually quite a strong Medieval tradition about wild men, and it seems that it's been largely forgotten nowadays, although some old heraldic imagery still maintains an echo of it. Tolkien was familiar with it; both Beorn and the Drúedain draw on the idea, although in different ways, obviously. With the Drúedain, Tolkien even used a lot of the old words from Anglo-Saxon to refer to them, calling them both Woses and Púkel-men. Wood-wose is still the correct term in English to use, although it's a very old term that one doesn't hear often, obviously. And Púkel-men means literally "goblin-men" in Old English, and is the root word of the word puck or pooka, a kind of nature spirit of old English folklore.
Although not necessarily drawn from exactly the same well, several settings that I enjoy have wild men analogs. In Eberron, you've got the shifters; humans who are touched with just a bit of lycanthropic blood. In the case of Eberron, this is more a case of developing a visual image and racial powers than it is in exploring the concept of the puck or woodwose archetype, although of course there's no reason why you couldn't do that with the race. I quite like the mechanical implementation of the shifters; they're a bit fiddly and complex, but not too badly so. Plus as a confirmed ranger and other outdoorsman archetype fan, I've had a lot of fun playing shifters in the past. Once of the highest level characters I ever played was my shifter (who's name escapes me, but it was vaguely Slavic in derivation, and I think I might have given him the last name of Leshovik, in honor of the slavic version of the wild man myth). He was a shifter barbarian/ranger, who also used the Reachrunner prestige class from Races of Eberron. Fun character.
Privateer Press, as is their wont, went a little bit darker with the tharn, a race of feral humanoids who also can shapechange slightly--although not like a true werewolf--who are terrifying, violently xenophobic hunters of some of the darkest and thickest woods on the planet. They got adopted wholesale into the Circle Orboros faction when the Hordes game was released, so they work with the druids and others to fiercely worship the Devourer Worm; a kind of personification of the harsh, "red in tooth and claw" aspect of nature. But in visual and mechanical concept, the tharn aren't really much different than Eberron's shifters. It's in "fluff" concept that they're different.
I like the idea so much that I want to introduce it to my games on an ongoing basis. I've gotten rid of most of the "standard" races of D&D over time. It's rare for me to use elves, dwarves, half-elves, gnomes, or halflings. I'm often on the fence about orcs and goblinoids; making them be the same boring adversaries that we've seen for decades is lame, but making them be regular old PC-viable races is still an unusual and thus intriguing concept. But other times, I don't even want them, going for a more humano-centric theme. But even in my humano-centric theme, I accept the idea of magical or unearthly bloodlines, hence my use of the tieflings and now, a kind of dark, violent, feral, fey-like race.
I think I'll use the old English word and call them pucks, at least as a slang-term (maybe vucari as a "real" term.) Wood-wose would be great, except that Tolkien kinda spoiled it for everyone else. I don't know how easy it'd be to get past images of Ghan-buri-ghan anymore. In concept, I'm leaning more towards the tharn concept--the pucks are not friendly, and you don’t want to meet them. But some of them do trade and interact with other people; a monolithically isolationist population is hard to imagine in the real world, and equally hard to really do well (and make interesting) in a fantasy world. Mechanically, I'll use the stats for shifters, which appear in several 3.5 era D&D books, including the Eberron Campaign Setting, Races of Eberron, and Monster Manual III.
In terms of image, if you could take Wolverine or Sabertooth of Marvel Comics fame out of their spandex and dress them like hippy-Conan the Barbarian wannabes, you'd have just about the right image. I might throw up a few sketches if I can get to it; it's been too long since I've been able to draw like I used to like.