Gargish Silver Horn
The great silver serpents that roamed the Realm of the Gargoyles were on occasion used by Gargish warriors to strengthen themselves before battle, with war parties seeking out and slaying such creatures before partaking of their venom—which sent them into a berserker-like rage. Presumably, the silver horn played a role in such undertakings, serving to lure the beast to the location of the company that sought to harvest its poison.
During the time of the Avatar's adventures regarding the Black Gate, such a silver horn had come to be housed in the Royal Museum of Britain, as part of an ongoing exhibit of artifacts revolving around the quests of the Avatar. Fortunately, when sounded within Britannia's capital at this point in time, no silver serpents appeared in answer to its call.