The "Night Hag" phenomenon

"Night hags", or supernatural entities causing sleep paralysis, are apparently a global phenomenon in folklore (up to and including 20th century UFO abductions).

In German folklore, they have lots of different names depending on the region: Alp, Mart, Walrider, Incubus, Nachtmahr, Drude, Doggi, Schrätling, and so forth. They can be divided into three broad categories:

• Nonhuman spirits such as demons or "fairies" (although German folklore does not use that term as such)
• Witches
• People whose spirits roam while they are asleep, and then torment other sleepers. This is generally not under their conscious control, though sometimes it is portrayed as an addictive urge.

I was wondering what other examples of "night hags" you know from folklore and mythology around the world?