In the final scene of the movie Easy Rider, the redneck in the pickup truck who shoots Wyatt and Billy has a large goitre on the right side of his neck.
If no other source of iodine is in the diet, drinking the river water can lead to an enlarged thyroid gland, a condition is known as "Derbyshire Neck", or Goitre.
In interviews Gretz jokingly claimed it would be titled The George Lucas Neckfat.