Marilith

The Marilith is one of the most famous and easily distinguished of the Tanar'ri of Dungeons & Dragons. These powerful and deadly demons are amongst the highest classes of demons that aren't actively Demon Princes, and traditionally serve as the tacticians and generals of the Abyss. The Baatezu absolutely hate them, because they are both Chaotic and highly intelligent, allowing them to form complex plans and tactics that use innovation and free-thinking the hidebound Lawful devils are incapable of matching. Worse, they're extremely deadly combatants, deftly wielding six enchanted weapons - traditionally all swords, but this is hardly set in stone - to eviscerate entire armies of lesser beings that dare to challenge them.

In all honesty, though, the Marilith is probably so famous amongst fa/tg/uys because they are one of the hottest demons in all of D&D. Appearing as sexy, six-armed warrior-women with the lower bodies of giant snakes (very much like an Amazonian, multi-armed lamia), the Marilith has long competed with the Succubus in the eyes of many fans for the title of "sexiest she-demon". The game's producers even take note, admitting that mariliths are common courtesans or harem-mates for Demon Princes and other Abyssal nobles.

Though usually placed lower down on the totem pole, mariliths actually have their own demon princess; Shaktari, the Queen of Mariliths, appears as a Gargantuan-sized marilith with jet-black skin and scales, a rattlesnake's tail, eight arms, blood red hair, long downwards-curving horns, and burning red eyes. Appearing in the final print issue of Dragon Magazine, #359, it's stated that she spent untold centuries imprisoned in the Wells of Darkness, only to be mysteriously released in "recent times". Shaktari rules over Vudra, 531st layer of the Abyss, a sweltering tropical plane consisting of myriad islands crawling with all manner of poisonous animals and plants amidst a roiling sea of venom and blood. Vudra actually was first detailed in Dungeon Magazine #60. She's a 30HD Gargantuan Marilith with the Demon Lord template, plus the additions of the spell-like abilities Fly (at-will), Haste (3/day), Banishment (3/day), Freedom (1/day) and Imprisonment (1/day), two extra weapon attacks due to her extra arms, the Aquatic subtype with the Amphibious extraordinary ability, dishes out a 3d6/3d6 poison with her weapon and tail slap attacks, and has an Aura of Toxin that nullifies any poison resistance/immunity and spells that purify poison within 120 feet, unless she deigns to spare a victim from its effects. She is mostly favored by serpentine races, obviously; evil nagas and serpentfolk make up the bulk of her mortal worshippers, although the serpentine lamia nobles are also possible worshippers.

Ironically, despite being iconic D&D monsters, the mariliths are actually Open Game License, which means they appear in Pathfinder as well. Created from the souls of the most arrogant of evil rulers and warlords, mariliths in Pathfinder embody the sins of Pride and/or Envy; cursed to forever be the penultimate demons, no matter what they have, it's never good enough. They even have the ability to shed their skin, completely reinventing their appearance on a whim, to exemplify this constant need to be better. This sometimes leads to strange mutations; for example, Lixiriltha, the Jade Coil, has the serpent-nest hair and petrifying gaze of a medusa (she turns her victims into jade statues) and a secondary serpentine maw at the tip of her tail.

For those Pathfinder fans who want to really indulge their perverse lust for mariliths, the "Demons Revisited" sourcebook contains rules for specifying the Half-Fiend template into a Half-Marilith:

+6 Str, +4 Dex, +6 Con, +2 Int, +2 Wis, +4 Cha

+2 Natural Armor

Does not gain a Fly speed.

Gains a Tail Slap attack with the Grab & Constrict properties.

Gains 2 extra arms.

Gains the Multiweapon Mastery Extraordinary Ability, which negates all penalties to attack rolls when fighting with multiple weapons.

Replaces its Desecrate SLA with Fly, Poison 3/day with Greater Magic Weapon 3/day, Contagion with True Seeing, Unhallow with Greater Teleport, and Horrid Wilting with Blade Barrier.

Challenge Rating increases by +1 from the standard Half-Fiend.