Knickerbocker was a toy company founded in New York in 1850. They are well known for manufacturing plush toys, though they also released early action figures of Lord of the Rings, a doll line based on the Annie comic strip, and this disturbing piece of E.T. merchandise. Among their plush offerings in the 1970s were superheroes with velcro on their hands and feet to allow them to be posed, including Spider-man, the Incredible Hulk, and this Superman doll dated 1979.
Superman stands 19″ tall, and the box is a whopping 21″ high by 15-5/8″… it makes for an impressive display, especially with the great illustration of Superman on the front and back. Superman himself is a little goofy as you might expect from a plush. Oddly enough, the likeness reminds me of Sid Vicious. Mine has a SKAGGS price tag on it, too.