At Korean World of Warcraft community site, I found some interesting screenshots and it seemed legit.
Along with Rogue Batman screenshot, theres Spectral Gryphon and Wyvern mounts picture.
(I don't know those mounts actual names. Just guess...)
Since it's not on mmo or warcraft facebook photos, decided to upload these.
blog page: durl.kr/gyjuw(page deleted)
EDIT : What is happening....they deleted that blog post.
Another kind of 'accidently' leak? But photos still exist as below addresses.
Sorry for that I can't post image directly yet so just posted website addresses.