His role in Tolkien's writings is so slight that it has been described as a plot device,[1] though scholars have noted his contribution to the evident paganism in Middle-earth.
Some aspects of his characterisation were invented for the films, but the core elements of his character - namely communing with animals, skill with herbs, and shamanistic ability to change his shape and colours - are all described in Tolkien's works.
[T 2][2] Radagast lives at Rhosgobel on the western eaves of Mirkwood, its name deriving from Sindarin rhosc gobel meaning "brown village".
[T 5] The in-fiction etymology, according to the essay "The Istari" in Unfinished Tales, is that the name Radagast means "tender of beasts" in Adûnaic, one of Tolkien's fictional languages.
However, Christopher Tolkien says that his father intended to change this derivation and bring Radagast in line with the other wizard-names, Gandalf and Saruman, by associating it with the old language of the Men of the Vales of Anduin.
[1][2] He has been described as "one of the most interesting enigmas in Tolkien's writings"; given the treason of Saruman, he and Gandalf are the only two wizards available to counter Sauron, but Radagast fails to answer Elrond's call.
[T 6] Christopher Tolkien commented that Radagast might not have failed completely, as he was specifically chosen by the Vala Yavanna for a mission to protect the plants and animals.
[T 1] The Tolkien scholar Patrick Curry writes that the Slavic Radagast is the pagan patron of the Czech Beskyd mountains, depicted with a bird atop his horned helmet.
[10] McCoy stated that he saw Radagast as "very otherworldly with, as Tolkien depicts him, an empathy and kinship with nature, a Middle-earth version of St Francis of Assisi".
[10] Radagast meets Gandalf, Bilbo Baggins, and the Dwarves en route to Erebor, and tells them of his discovery in Dol Guldur.
[12] The writer Brian Sibley comments that the fact that Tolkien said little about Radagast gave Jackson's screenwriters freedom to make of the character what they liked.
[13] The sled chase was filmed in the Strath Taieri glacial valley of New Zealand's South Island, strewn with real boulders.