Complex sentence: Radagast the Brown is one of the five Wizards in J. R. R. Tolkien's fantasy epic "The Lord of the Rings" and is mentioned in "The Hobbit".
Split into simpler sentences: Radagast the Brown is a fictional character in J. R. R. Tolkien's Middle-earth legendarium. He appears in "The Lord of the Rings" and is mentioned in "The Hobbit".