Bitterest Balebrew Charm

Bitterest Balebrew Charm is a trinket for all classes. Its stats scale to your level when acquired.

Source
This item is a possible drop from Coren Direbrew in the Grim Guzzler of Blackrock Depths during Brewfest.

The Brewmaiden
Use of this trinket brings forth a red circle of light (like that of the Elune Stone, but red), framing the Black Brewmaiden.

Wave at her, and she will throw a Brewfest Brew to you.