WoWDB

This item is the only white "wizard hat" in the game.  It had a very low chance of being looted from  Spoils of Theramore, which was rewarded for completing the special level 85 version of the Theramore's Fall scenario prior to the release of the Mists of Pandaria expansion.  Due to how stats worked at the time, it was possible for a mage or warlock to obtain the hat despite it having the spirit stat on it (spirit has since been removed entirely in Legion).  I can personally attest to this, as I obtained it on my mage alt.