His true form is a spider like creature, his bottom half is a spider and his top half is of a human but is jet black, he has a mask over his face with a crack though it.

Iyoui is REAL and DANGEROUS, if you see him in your nightmare then it is best to wake up or get away as fast as you can.

In a nightmare i found a book about Iyoui but lost it, and it was to dark to read it. If found please put contents on this page.

Any and all people who have seen or heard of iyoui say so, if you think you have seen him in another form say so!

More info is needed, this is a very little amount of what can be learned