Foxhead medallion
From A Wheel of Time Wiki
The silver foxhead medallion is a ter'angreal that was given to Mat Cauthon when he emerged from the Rhuidean twisted-door ter'angreal. It is one of his most prized possessions, and he refuses to part with it under any circumstances, though he did once offer it as protection to Elayne.
The foxhead will disrupt flows of the One Power aimed at the bearer. For some unknown reason it also injures a gholam on contact, burning it as if the medallion were red-hot metal. The foxhead does not, however, affect actions of the Power which are not directly aimed at the bearer. For example, although a binding formed of Air will melt away upon touching the bearer, a stone thrown by a flow of Air will strike normally.
Though Mat is unaware, a side effect of the medallion is that it protects dreams. This was not part of the intended purpose of making the medallion; it's a true side effect.[1]
