One of the many American Giants - a Muffler Man located in Crystal Lake, Ilinois.
Now in short about Muffler Men. They are giant fiberglass sculptures used as "attention grabbers". Many of these figures were used to promote various roadside businesses and often would hold real merchandise, like full-sized car mufflers, which, as I understand, was the reason for the Muffler Men nickname.
The figures are usually 18–25 feet (5.5-7.6 meters) tall. Muffler Men were a popular roadside decoration in 60's and 70's mainly in the United States.