Succubus
Succubi are one of the oldest forms of monstergirls in Western culture, being that they are naughty she-demons who visit people in the middle of the night to have sex with them. They began in medieval Christian tradition as an explanation for morning wood, wet dreams and unexplained pregnancies (courtesy of their male equivalents, incubi - said in some lore to actually be succubi shapeshifted into male forms after they harvested semen by having sex with some man), and have developed from there.
Common attributes; really horny and/or very good at sex and shapeshifting. Many protray them as able to weaken or even kill people with a touch/by kissing them/by having sex with them, since they're supposed to be scary demons and "sexy woman who willingly jumps your bones in the middle of the night" isn't as scary now as it was back then. They tend to be the demons most tolerant of mortals, and even prone to falling in love with them.
Daemonettes are one of the more fucked-up incarnations of succubi in modern culture, being not only sex-crazed she-demons, but also soul-eating monsters AND sadomasochistic psychopathic killers, so they love to mix sex and violence in ways that they really, really shouldn't be mixed.
Succubi in D&D
Naturally, in Dungeons & Dragons, succubi have been around since the beginning.
Originally, they were classified as Demons, on their basis of being all about tempting mortals into sins of passion. Since these were the days of alignment-based grid-filling, naturally, they got a Devil counterpart, the Erinyes. They also had two half-fiend offspring unique to them; the female alu-fiends and the male cambions, though after 2e "cambion" became a more general term for a half-fiend in general.
In 4e, Demons and Devils were separated from their former alignment-based nature. Demons became elemental forces of destruction and madness, whilst Devils became corruptors and soul-harvesting manipulators. For this reason, the succubus moved over to the Devil side, since "seduces mortals into giving up their souls" is closer to the devils' schtick than it is the demons' "destroy everything, drive people insane, let the multiverse burn!" The Erinyes remained in this edition, and was still a devil, but became a ruthlessly disciplined warrior-bitch instead of a seductress.
In 5e, succubi got separated from the Demon/Devil divide entirely. They're now a Neutral Evil race of soul-harvesting hedonists who can be found throughout the Lower Planes, happily living alongside demons, devils, yugoloths, rakshasas or whatever so long as they get to keep getting their rocks off. Given their alignment-free nature they've become something of a counterpart to the angels employed by various Good deities. Eirenyes remain Devil warrior-bitches, which is fitting since their name comes from the Greek spirits called the Furies who were divine punishment for particularly nasty shit.