Houri

Houri are the womanly delights apparently promised the devout Muslims in Paradise.

More on womanly delights
They are, allegedly, perpetually virgins, despite any sexual congress they engage in and, in an odd echo of the myths surrounding Mary (Mother of Jesus), their virginity is  miraculously restored after each session of intercourse.

These beings seem to be remarkable in some ways, as we are told by Muhammad al-Bukhari in his collection of Hadiths Sahih Bukhari:

All of which (especially the "sixty cubits" part, which would make them 90 to over 100 feet tall [depending on your cubit], and a proportionally sized vagina about half a meter in diameter) may go some way to explaining their perpetual virginity. All in all, this scenario suspiciously resembles a teenage boy's fantasy, which may provide some insight into the intended target demographics of the original preachers.

Ghilman
The ghilman (ghulam in singular) are eternally youthful boys that serve both men and women in Paradise, and are often likened to waiters or eunuchs who serve their masters. Incidentally, the word "ghilman" was also the name for slave-soldiers in the Ottoman, Mughal and Persian empires.