
The umbrella necktie is around Neptune's neck
The Umbrella necktie was an invention by Doc Brown. It was an umbrella with a loop around the handle so that it could be worn as a necktie.
In September 1984, Marty McFly found the umbrella necktie around the neck of a statue of Neptune, while searching Doc's garage for something to use in the science project assigned by his teacher at Hill Valley High School, Mrs. Zawadski.