Today is the last day to obtain the Hood of Hungering Darkness helm transmog via Prime Gaming. Starting tomorrow, Crown of Eternal Winter will be available instead.
For those that missed it, three helms previously available on the Blizzard Shop will be obtainable through Prime Gaming in the next few months:
Jewel of the Firelord: Was available until July 26
Hood of Hungering Darkness: Available now, last day to claim today, August 23
Crown of Eternal Winter: