A broken horn that you obtained from defeating the Wolflord. That said, it should not have left anything behind after your hunt.
Even a lord among the Riftwolves is nothing before monsters of a higher pedigree.
"Gold" mass-produced these malformed wolf packs almost as if by accident, like shrunken drawings on discarded sheets of paper, and the horns on this one represent its authority to command its dark brood to dissolve space itself.