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.
Eagle (Middle-earth)
The Great Eagles ruled by "Thorondor" ["sic"] already appeared in the first tale about Middle-earth that Tolkien wrote in late 1910s, "The Fall of Gondolin", published in "The Book of Lost Tales". The role of Thorondor was expanded in stages, with the successive introduction of the relevant plot elements; and after the conception of Númenor entered in 1930s, the notion that the eagles were the messengers of Manwë was further elaborated. Soon after, Tolkien introduced the eagles into "The Hobbit" and "The Lord of the Rings", repeating in the latter some plot elements and names present in older writings.