Thomas Nast was an American cartoonist and caricaturist who was active in the late 19th and early 20th centuries. He is best known for his satirical cartoons and illustrations that were published in Harper's Weekly, a popular magazine of the time. Nast is credited with creating the modern version of the Republican Party elephant and the Democratic Party donkey. He also created the modern version of Santa Claus. Nast was a strong advocate for civil rights and was critical of the corruption of the political machine of Boss Tweed.