Around 1813, he changed his third baptismal name from Wilhelm to Amadeus in homage to Mozart, after which he composed a ballet, Arlequin.  
One of his two novels was the Life and Opinions of Kater Murr.  Around 1813, he changed his third baptismal name from Wilhelm to Amadeus in homage to Mozart, after which he composed a ballet, Arlequin.  Following that he released  his most popular work, the collection Fantasy Pieces in the Manner of Callot.  Largely remembered for the collection the The Serapion Brethren, the novel The Devil's Elixir, the story "The Sandman," and the opera Undine, FTP, name this German writer whose stories inspired an opera by Jacques Offenbach.
One of his two novels was the Life and Opinions of Kater Murr.  
E.T.A. Hoffmann