Sea Serpent is a giant balloon that appeared in the Macy's Thanksgiving Day Parade in 1941.
History with the Macy's Parade
The Sea Serpent made his lone appearance in the 1941 Macy's Thanksgiving Day Parade. Unlike many other balloons, this balloon did not use helium. Instead, it was filled with air, with the handlers lifting the balloon down the Parade route.
After United States became enlisted to WWII, Fiorello La Guardia plunged a knife to the Serpent, signaling that the parade would go on hiatus during the war, and the balloons would be recycled into the 650 pounds of rubber donated to the U.S. military.