Watson is the faithful dog owned by Sherlock Hemlock. Appearing in "Mysterious Theater" sketches on Sesame Street, Watson often sniffs out the solution before his master, and tries, unsuccessfully, to communicate that fact through barks and whines. His name is a reference to Sherlock Holmes' companion Dr. Watson.
Watson's first known appearance occurs in the book A Bird's Best Friend, where he was depicted as a medium-sized long-haired orange-brown dog in a deerstalker cap and matching coat like Sherlock's. In his Muppet appearances, Watson is a smaller brown dog who wears only a collar.