Attack on Shoyul Ghoul
Medallion with fox head
The foxhead medallion is a ter’angreal that melts the flows of the One Power; the bearer won’t be touched by them directly. As the name indicates, the form of the silver ter’angreal resembles the head of a fox, its one pupil bearing the ancient symbol of the Aes Sedai, a tiny circle split by a sinuous line, one side polished bright, the other shaded in some way.
The medallion grows cold when someone holds or channels the Power close by, colder than ice in the immediate vicinity and merely cool some distance away. It detects both saidin and saidar.
Direct weaves like Healing or Compulsion don’t affect the wearer as long as his skin touches the medallion; flows of the One Power will simply vanish. Indirect channeling like lightning or throwing a stick at the wearer works, however.
The medallion also burns a gholam’s skin: “Smoke rose around the edges of the foxhead, and a sizzle like bacon frying (…) A raw red brand marked where the foxhead had fallen.” The medallion does not heat up during the process. A theory on how that is working can be found here.
An unintentional side effect of the foxhead is warding the bearer’s dreams.