I logged in today despite the authentication issues only to see the awful visual bug, I tried changing my graphic settings, update my drivers, go to the barber shop and tried changing looks. Nothing helped.
2 Likes
I am having the same issue. Do you by any chance have an AMD cpu? Phenom II or similar? Looks like the cpu is an issue. Lots of threads on the US forum about this. Awaiting a fix I believe. It has been like this all through BETA and PTR.
https://eu.forums.blizzard.com/en/wow/t/hair-textures-and-eyes-black/182806/32
And
https://eu.forums.blizzard.com/en/wow/t/black-eyes-and-hair-textures/192827/32
Join the club 
From what I managed to gather the issues occurs because the game doesn’t support some older cpus that includes all AMD Phenomenon. Blizz is aware and is working on solving this. https://us.forums.blizzard.com/en/wow/t/amd-missing-character-textures-after-90/675921/470
All fixed - On live version now!