Dan'l Webster is a fictional character from the short story "The Celebrated Jumping Frog of Calaveras County," written by Mark Twain. He is a frog trained by a man named Jim Smiley to jump higher than any other frog. The story is set during the California Gold Rush and highlights themes of deception and competition. In the tale, Dan'l Webster is challenged to a jumping contest against another frog. However, Smiley's opponent tricks him by filling his frog with quail shot, making it unable to jump. This humorous story showcases Twain's wit and captures the spirit of American folklore.