Lamia
A Lamia is a sort of monster that combines human and snek features, commonly having a human torso from the waist up and a snake body from the waist down. The term naga is sometimes used interchangeably, but they are just as likely to refer to distinct creatures.
They tend to share a lot of stereotypical snake traits, like preferring to sneak around and plot rather than fight in the open. An affinity for magic, poison, or hypnosis is also common.
Nagas
When nagas and lamias are distinct, nagas tend to be the ones with more snake features. Exactly what that means depends on the interpretation.
In Dungeons & Dragons, for example, Nagas resemble giant snakes with human heads, which is how they are actually described in the Hindu religion they originated from.
In more monstergirl/furry communities, nagas are basically lamias (humanoid upper torso, giant snake's body from the wast down), but with scaly skin on their upper torso as well (normal lamias, like your typical merfolk, are depicted with human skin giving way to scales). Sometimes, they may go so far as to have anthropomorphic snake's heads atop their human-like shoulders, but this is most common amongst furry artists.
Finally, a naga may be described as having an "armless" humanoid upper torso (with said torso potentially overlapping with the aforementioned "scaly-skinned humanoid and/or snake-morph upper torso" depiction). What this basically amounts to is the "human-headed snake" naga, but with boobs, so it's pretty much only seen in monstergirl porn - it allows one to mix "monstergirl" with "amputee" fetishism.
On the other hand nagas in hindu mythology are actually presented multi-armed when in their human/snake form (they also can shapeshift into an actual snake).
Dungeons & Dragons
Dungeons & Dragons lamias are totally different from other lamias. Since their first appearance in the Monster Manual for Advanced Dungeons & Dragons 1st edition, typical lamias were described as centaur-like meldings of woman and quadruped beast. Their 2nd edition updated appearance, the Monstrous Compendium volume 2, specifically stated that their lower bodies can resemble goats, deer or lions, among other things - however, as all of the artwork for lamias has traditionally gone with the "lioness-taur" appearance, this has become cemented in peoples' minds as the "true form" of the D&D lamia. Although, strangely, their appearance in 3.5's Monster Manual depicts a male leonic commoner lamia.
However, the iconic snake-girl lamia has also appeared in D&D as well. Called the Lamia Noble, and coming in both male & female forms (males are sword-wielding gishes, females are spellcasters), it appeared for the first time in the Fiend Folio and was later reprinted in typical "subvariant small addition" in the Lamia's entry in the Monstrous Compendium. It would not be updated to third edition until Expedition to the Demonweb Pits, late in the game's run-time. The biggest difference, aside from the added wizard/sorcerer spells, is that they can shapechange into human form.
Lamias had their own Ecology Of article in Dragon Magazine #192. According to this article, noble lamias need human mates in order to propagate their species, as interbreeding with each other or with common lamias will only produce more common lamias. Likewise, the common lamias need to mate with humans to produce true offspring, as mating with each other will only produce sa'irs, which are savage beasts that have the forequarters of a goat-horned lion and the hindquarters of a goat... No, you didn't read that wrong; according to Drag-Mag, common lamias, despite looking like women from the waist up, are actually a species of hermaphrodites and so can impregnate and be impregnated as they see fit. Lamias of both "castes" have an annual week-long mating season in summer that drives them wild with lust and sends them looking for human baby-daddies/mommies; a sufficiently attractive human partner could cause them to go into heat outside of this time as well. According to Drag-Mag's statistics, adult commoner lamias are 60% likely to be lion-taurs, 25% likely to be goat-taurs, and 15% likely to be deer/antelope-taurs. Lamia nobles, according to this, can't actually copy spells from scrolls or spellbooks (remember, these were the days before monsters could have classes), so human wizards were especially prized captives.
Traditionally, lamias of all kinds are Chaotic Evil in alignment, being selfish, evil, cruel, lazy hedonists who use their innate ability to drain Wisdom in order to brainwash victims into serving them as slaves, mates and/or food; they don't respect any life other than their own, so the roles are not exclusive.
A variant lamia called a "Tigerus" is native to the Kingdoms of Kalamar 3.5 setting, making its appearance in the setting's personal monster manual, "Dangerous Denizens: The Monsters of Tellene". Unlike common lamias, these are a neutral-aligned species of tiger-taurs who live a stone-age style primitive lifestyle (to put this in perspective, cooking meat is a new and exotic idea for them, though quickly catching on). They lack the Wisdom drain of standard lamias, instead focusing on melee combat (pouncing and raking special attacks), and they sport druidic spells that make jungle life easier, like Speak With Animals, rather than the standard sorcerer powers.
4th edition is an outlier in this regard, as its "lamia" has absolutely no relation to the model portrayed here and which it returned to in 5th edition. Instead, its "lamia" is a species of carnivorous scarab-like beetles native to the Feywild with a voracious appetite for fey flesh (although they'll eat humanoids if they can get them). Their standard hunting MO is to eat the poor bastards alive from the inside out, hollowing out the corpse so they can wriggle under the skin and use the skeleton to move the bug-bag corpse around as a disguise. This lets them get closer to fresh victims. Although this is an awesomely creepy monster idea, its poor choice of name alienated a lot of fans and so it's gone unused since.
Pathfinder
Pathfinder's lamias are pretty much exactly the same as their D&D ancestors; the biggest change-up was the creation of the "Lamyros" subtype. Having a family of "lamia-kin" allowed Pathfinder to not only bring back the Lamia Matriarch, but also add some new members to the family -- these first appeared in the original Rise of the Runelords adventure path, but were tweaked when it got reprinted in compilation form under Pathfinder's "new" ruleset.
The Harridan is an elite Lamia, the only creature more important in their loosely-held society than a Lamia Matriarch. It's essentially a giant lamia with added divine spells, and was tweaked to a template only available to lamias with 10+ levels in a divine casting class in the compilation. This "remake" version does state that it's possible to encounter Noble Lamias turned Harridans, but it's very rare, and most are the typical leonic tauress.
The Hungerer is a result of Karzoug experimenting on Harridans in his fleshwarping pits, creating a horrifically disfigured, gaping-mawed, obscenely obese monstrosity that suffers endless pain & hunger, causing it to devour anything and everything around it.
Finally, the Kuchrima is the bottom of the lamia totem pole, being a hideously ragged-looking humanoid vulture that serves as a scout and, more eagerly, garbage disposal; noxious cannibals and gleeful scavengers, these carrion-eaters carry huge bows they use with their prehensile feet from the air and carry foul diseases up close in melee.
A 3rd party netbook, Kobold Quarterly #23, includes unofficial rules for playing a "classic" snake-woman Lamia in Pathfinder or D&D 3.5 in the form of the Lamia Commoner species. It has the following racial profile:
- +2 Strength, +2 Charisma, –2 Intelligence: Lamia commoners are physically strong and manipulative.
- Medium: Lamia commoners are Medium creatures, and have no bonuses or penalties due to their size.
- Normal Speed: Lamia commoners have a base speed of 30 ft. They have a climb speed of 20 ft and a swim speed of 20 ft.
- Darkvision: Lamias can see in the dark up to 60 ft.
- Low-Light Vision: Lamias can see twice as far as humans in dim light.
- Intimidating: Lamias receive a +2 racial bonus on Intimidate skill checks due to their frightening nature and appearance.
- Lamian Immunities: Lamias get a +2 racial bonus to saves against mind-affecting spells and effects.
- Snake Body: Lamia commoners have neither feet nor legs and thus cannot be tripped. They may not use magic items requiring the feet slot.
- Skilled: Lamias receive a +2 racial bonus on Bluff and Use Magic Device checks.
- Spell Resistance: Lamias possess spell resistance equal to 5 plus their class levels.
- Spell-Like Abilities: A lamia can cast charm person and ventriloquism each 1/day, using her total character level as her caster level.
- Weapon Familiarity: Lamia commoners are proficient with the scimitar.
- Languages: Lamias begin play speaking Common and Draconic. Lamias with high Intelligence can choose any additional bonus languages, with Abyssal being the most typical.
Notable Lamias
- Ssen Patrick, protagonist of Lamia Daughter Quest.
- Miia (also romanized as "Meer"), the first non-human main character of the "Daily Life with Monstergirls" manga (and also the first member of the main character's unwanted harem).
See Also
- Lamia child, an old story of a paladin who kills a family of lamias, and decides to adopt the newly-orphaned child as a sort of penance.
- Lamia Daughter Quest, the sequel to the above, in which /tg/ is the lamia daughter, all grown up.
- Snek, a slang term for Lamias and other snake-like creatures.