Class: The Spider-Woman

The Jorogumo, a fey race of spider-women. Possessing many gifts of their arachnid nature as well as an uncanny ability to disguise their true nature. Deceivers and predators who use their innocuous appearance to lure in husbands, food, or both. 

The Jorogumo are naturally attracted to particularly glamorous, exciting humans and enjoy using their particular gifts to gain the trust and affection of these humans. As such, it is not uncommon for one of these strange spider-women to accompany a party of adventurers, using her arachnid abilities to aid the group. Normally, her aim in such an endeavour, beyond the fun of adventuring and the chance to refine her skills, is to slowly groom one of her companions to become her husband.

Since there are no male Jorogumo, they rely on human men for husbands; the children of such a pairing are human (with perhaps a slight spidery hint to them, and a touch of the strange) if male, and another Jorogumo if female. Sometimes, the Jorogumo will feel genuine affection for this human husband, and potentially settle down with him for a heart-warming retirement. Where this affection is lacking, however, she probably feels little guilt about eating him once the honeymoon is over, to better keep her secret.

Statted for LotFP, but other systems can probably use this too.

Basics of the class:

Hit Dice: D4 (IE as a Magician)

Attacks: No progression (IE, as a Magician)

Saves: As a Magician

XP to level up: As a Magician (2,250 to reach level 2 in LotFP)

Other details: If your system restricts weapons and armour by class, the Jorogumo suffers the same restrictions as a Magician would. If your system limits certain classes to particular alignments, Jorogumo must be Chaotic. If your system uses Prime Requisites, the Jorogumo's prime requisite is Charisma.

Special Abilities:

True Form: A Jorogumo appears as a five-foot-tall humanoid with arachnid features in her true form. Her head likely possesses the circular eyes and Chelicerae of a spider, and perhaps pedipalps as well. She may have additional limbs, a bulbous thorax, a chitinous exoskeleton, and so forth. This appearance, while off-putting, is purely cosmetic, and she functions like any other humanoid being save for the abilities listed below.

Human Disguise: A Jorogumo can disguise her appearance to look like a human woman. The appearance assumed is distinctive to each individual Jorogumo, but always young, attractive and slightly vulnerable-looking. This is essentially an illusion, the Jorogumo using mimicry and subtle camouflage to pass herself off as human, although a trained observer can often spot subtle tells. She can assume human appearance in a matter of moments as often as she wishes, but must be totally unobserved to do so. Likewise, abandoning her disguise happens immediately as soon as she stops making the active effort to maintain it, including while she sleeps, or uses any of her specifically arachnid abilities. Other tasks such as feeding, dressing and so on will require her to clever in order to avoid breaking her disguise or arousing suspicion. While disguised as a human, she gets +1 to her Charisma modifier, but cannot use any abilities that rely on her arachnid nature such as spider climbing, webs, and so forth. 

Arachnid Anatomy: A Jorogumo must consume appropriate food for an arachnid in order to avoid starving; she can only gain nutrition from draining the fluids from living prey, as her digestion is not able to handle solid matter or plants. Furthermore, the nature of her exoskeleton means she takes double damage from crushing, smashing, or squashing damage (such as hammers, things falling on her, and other blunt trauma). These weaknesses apply in both her true form and her human disguise.

Spider Climbing: While in her true form, a Jorogumo can climb like a spider, essentially being able to cast Spider Climb at will. Doing this requires that she make use of her skittering limbs and weird locomotion, so attempting it while disguised as human breaks the disguise and so reveals her true form.

Spider Fangs: A Jorogumo's fangs can be used to attack, dealing d8 damage when she bites. Biting in this way, obviously, will reveal her true form if attempted while disguised.

Speak with Spiders: While in her true form, a Jorogumo can speak with spiders, indluding natural small spiders, giant monstrous spiders, and monsters with arachnid properties such as Ettercaps, in their native tongue. Doing this requires her to use the rattles of her spider-fangs and to gesture with her extra limbs and pedipalps, so attempting it while disguised as a human breaks the disguise.

Webs: While in her true form, a Jorogumo can create silk from her spinnerets, essentially allowing her to cast Web once per turn. This web can have all the various properties of normal spider silk (varying strength, thickness, stickiness and so on) as well as the effects of the spell. Obviously, doing so requires that she use her spinarettes, and so will break her disguise if she attempts it in human form.

Living By Her Wits: A Jorogumo is not part of human society, and doesn't have access to the same resources that humans do. She begins play with only 3d6 silver to spend on equipment.