Incubi is the plural of Incubus.
This creature is as stunning and exraordinarily beautiful, with flawless skin and raven hair as is it's counterpart the Succubus. They have a tempting form rivalling those of the Succubi
. And therefor they are as dangerous to mortal women as Succubi are to mortal men.
Incubi are the most comely of male demons and they, like their counterparts, live to tempt mortals.
A Incubus is slightly bigger than a Succubus and stands about 6'2 feet (1.89 m) in its natural form and weighs about 145 pounds.
Incubi are not warriors. And will often flee combat whenever they can aswell as Succubi. If forced to fight, they can attack with their claws, but they prefer to turn foes against eachother. Incubi use their polymorph (shapeshifting) ability to assume a human form, and can maintain this form indefinitely. Their preferred tactic when dealing with heroes is to feign friendship and create an opportunity to be alone with one of them and uses suggestion spells to turn them on eachother. Even Incubi are not above taking the role of a damsel in distress when encountered within a dungeon. Though of course, they'd need a female paladin to majestically rescue them. Though, maybe a male one would do it aswell...
An Incubus, like a Succubus, can drain energy from a mortal by lureing one into some act of passion, or just by a kiss. This weakens the mortal yet often does not kill them.
It is also an expert in charming, tongues (it can speak all languages) , polymorphing, suggesting things in the mind of unwilling, and it can teleport itself. It also posesses a little telepathic powers.
An Incubus has darkvision, so it can see in the dark, it is also immum to poison, for the succubi come from a plane where poisons are omnipresent.
They make good characters for people who want to play with spellcasters that rely on enchantment effects and still have a few tricks when unseduceable creatures appear. Such as mages that rather have a new tome than a boyfriend. :/
sources: Fiend folio, Book of vile Darkness, Monstermanuals, wikipedia, wizard's site + forums