It is called Ero Guro, but is often shortened to just Guro. It is a Japanese art form that focuses on the bizarre,
gore, grotesque, and mutilation mixed with eroticism. In the West, gory
hentai is often referred to as Guro, especially if there is a heavily mutilated anime girl covered in blood, missing limbs (or other various body parts), or spilling organs. Often all three is present and the subject is deceased.
Items that are pornographic and
bloody are not necessarily ero guro, and ero guro is not necessarily pornographic or
bloody. The term is often used incorrectly by western audiences to mean "gore"—depictions of horror, blood, and guts.
"I walked in on my cousin
jacking to a mutilated, dead anime girl. There was blood everywhere!"
"That sounds
like Guro
dude."
"I seriously think I'm scarred now, it was terrifying."