[Lycanthrokeith]

Succubi are one of my favorite things to write/RP.

A lot of this will vary with the preferences you have and the story's world. I have my own personal preferences, some based on mythology, and most based on my own personal tastes.

My personal look/characteristics for a succubus:

--A flawless, enticing figure. This means more than just big boobs and a good-sized ass. Features like silky long hair, body and facial symmetry, clear skin count as well.

--Greatly enhanced strength, agility, speed, and resistance to harm. I sometimes give them hypnosis and/or a pheromone "charm aura."

--A body built for pleasure, one big erogenous zone. Certain parts will be more responsive than others, obviously. Their bodies are also highly adaptable to their lovers' desires, via their natural shapeshifting abilities. I also usually give them the ability to feel what their partner is feeling in addition to their own pleasure. This is yet another part of what makes them such able lovers.

--Pointed elf-like ears, upper and lower small fangs, moderate length claws.

--Demonic eyes. I usually go with black sclera (the white part of a human eye), vertical slits for pupils, and red or glowing red irises.

--A unique skin color. Pink, creamy orange, purple (dark or light), blue (medium or light) and crimson red are some of my favorite colors.

--Horns. I generally like two medium-length ones, usually onyx. Large ram-like ones are less alluring.

--A long spaded tail. Prehensile, and essentially a phallic appendage.

--Hooves and risen ankles. Not only are these classic demonic traits and alluring, but frankly, feet gross me out.

--Demon bat-like wings, coming from the upper back near the shoulder blades. I like them functional for flying or wrapping around themselves, large (the bottom tips just around the knees, the top tips above the head) and with a wide wingspan.

--I also like to do stories about succubi who aren't necessarily evil. Demon, in essence, means "outsider," and not immediately good or evil.
They often act in defense of women or men who are being preyed on by sexual predators, or are vigilantes who hunt down the wicked and deliver them to Hell for punishment, or simply just savor the good life and have fun, sharing their gift by transforming those they deem worthy. Sometimes they aren't beings of Hell in my works, but from another dimension, one of pleasure and indulgence without pain or punishment.

--Weaknesses can vary. If they're good-aligned, I usually make them unable to seduce anyone who refuses their advances. They also need to absorb sexual energies, and if they're evil, souls. I've sometimes given them allergic reactions to pure gold or holy items wielded by those with true faith. Whatever works for your plot can be effective.

Hope that gives you some ideas. Good luck!