It did not exist. That is one of the many new items in the new update that is coming up. Because the items are loaded into the server for testing, text translations, etc, they become available in the fishing part of the game - unfortunately. It would be nice for these items to first become available in the quests, shops, chests, etc first, but the fishing kind of spoils the surprises.
More importantly...
O.o is your mage wearing pants?
Blasphemy.
I didn't know some were coded to be worn by them.
It's the developers role to make changes that encourage gameplay in all of its aspects.
It's the players role to enhance gameplay and make it enjoyable for others.