Fourth Doctor Tom Baker’s iconic overlong scarf was an accident. Begonia Pope, the costume maker tasked with knitting it, misunderstood her instructions and used all the wool she was given. Baker loved it, and insisted on wearing it for the show. The scarf was originally twenty feet long.

The scarf in its original form was only seen in "Robot" and "The Sontaran Experiment," which was recorded right after "Robot." This particular scarf continued to both stretch and lose stripes due to wear and stunts. A stunt duplicate was also created that was shorter and had subtle color and pattern differences.

Back in the early '80s they made the pattern available (I think as part of a PBS pledge drive?) and my mom knitted me the scarf, full length I think, but not sure. It was epic (and mom too). Still have it!