Dungeons & Dragons has a long history of monsters who are only ever of a single gender, usually because that's how they were viewed in mythology. It has an equally long history of fucking up in terms of just what the results of humans banging those monsters would be.
Seriously, if all satyrs are male, then you would expect that a "Half-Satyr" race would be all-female, as it's only the daughters who fail to inherit the full bestial aspects of their faerie fathers. Likewise, if dryads and other nymphs are always female, you'd expect that only their sons would be tainted enough by humanity to be mere "halfbreeds".
Now, there is an explanation for this - it serves to "water down" the race enough that, in theory, it's a balanced PC option whilst still preserving the core foundation of the race - but it still is a huge logical cock-up.
Meet the hagspawn, perhaps the only "one-gender halfbreed" race to actually get things right.
Originating from Unapproachable East, a 3e splatbook for the Forgotten Realms "East Asia" regions, Hagspawn, as their name suggests, are the male offspring of hags. Unlike their "sisters", the changelings of Pathfinder, hagspawn get a real raw deal out of it. Like hags, they tend to be very big and very powerfully built, often with clearly inhuman markers (blue or green skin and red eyes, for example), and are frequently kind of ugly - in many ways, they're sort of like playable oni. Unlike hags, they have no real affinity for magic, instead being superhumanly strong and tough. They are resistant to enemy magic, though, which is kind of nice.
Hagspawn are called out as being "natural malefactors", which is a fancy way of saying "usually born evil". Of course, they don't pay a lot of attention to the possibility that this just might be because growing up in places like Rasheman, they tend to get demonized and scorned for their maternal lineage, until they ultimately decide to say "fuck you, if you want a monster, I'll be a monster!" and instead simply assert that hagspawn are naturally full of malice, violence and resentment.
But hey, what do you expect of a monstrous humanoid race in 3rd edition?
Needless to say, most hagspawn don't get along with anyone, although they tend to be less hostile with nonhuman races, seeing as how they often feel a certain sympathy for half-orcs and tieflings and many other humanoids are willing to judge them by deed rather than condemn them for ancestry. In one sense, almost all hagspawn are adventurers, with dim prospects for staying at home and living as normal members of a human community. Many are wandering brigands, thugs, and sellswords, never staying too long in any one spot lest their neighbors blame them for some crime or misfortune. Hagspawn make good fighters and rogues and are well suited to a life of violence and robbery.
They gravitate towards more chaotic company, for that reason: anyone who is willing to judge an individual on their own merits can potentially find a friend in a hagspawn. Whilst not particularly inclined towards religion, Hagspawn most often adopt a faith that appeals to the lonely, embittered, and vengeful. Bane, Shar, and Cyric are common patron deities, although the elemental fury of Talos and the battle skill of Tempus also speak to the hagspawn's violent nature. Good hagspawn most often worship the deity of whatever community they eventually find a home in.
The hagspawn are particularly common in Rasheman, and so usually speak that language and name themselves after it; they usually take simple human names (which, for a Rashemani hagspawn, includes Bor, Dor, Josel, Kurg, Sergel, and Vladir), and may or may not also use their father's surname. Hagspawn who don't care to hide their heritage, or who want to make themselves sound more fearsome, will adapt their monstrous mother's name for their own, and/or call themselves by the surname of "Hagson". Their haggish ancestry also grants them an affinity for the Giant language, and most learn the Common trading patois.
Hagspawn did get one day in the limelight though: One of them is a companion in the first expansion for Neverwinter Nights II. Gann(ayev) of Dreams is a strangely charismatic and attractive hagspawn. He's an epic level Spirit Shaman with a knack for seducing women in their dreams.