Sting (Middle-earth)
Sting has the magical ability to detect orcs or goblins nearby, glowing blue in their presence, as it did when the Fellowship encountered orcs in the mines of Moria. Tolkien establishes this as a common property of First Age Elf blades, particularly those forged in Gondolin. Sting is also exceptionally sharp. Bilbo manages to thrust it without effort deep into a wooden beam at Rivendell. Frodo also wounds a troll in Moria, after Boromir notches his own sword with his attempt. Sam uses Sting to cut through the giant spider Shelob's strong webs with ease, and also wound the spider, driving it away from the paralyzed Frodo.
Zygon
The Zygons appear in the New Series Adventures novel "Sting of the Zygons" by Stephen Cole, featuring the Tenth Doctor and Martha Jones, which is set in the Lake District in 1909. A plan to set up a royal funeral where the Zygons could replace the rulers of various nations is thwarted through the Doctor's intervention, as well as a Zygon civil war when one of their two Skarasens is killed.