[Gwathagor]

Sting wounded the cave troll, whose hide notched Boromir's blade. Plus all those countless victims during the Gondolin wars. And Shelob, the last child of Ungoliant the Great herself!

And if we're judging the entries by their enemies and victims, Carcharoth certainly gets some points. Huan...Beren...and then there's the Silmaril which he freaking ate. Not a lot of people can say that.