Shivers the Penguin was a character who appeared on Sesame Street during the late 1970s to early 1980s.
The puppet was designed so that Shivers could be carried by Big Bird or sit on Big Bird's lap. This allowed Caroll Spinney to perform both characters at the same time, with his left hand manipulating Shivers' mouth while his right hand worked Big Bird's mouth.
Shivers was mentioned in a New York Times article on Spinney, "At first, [Big Bird] was supposed to be only an incidental character on the show, but he drew so large a following he was soon one of the major Muppets. Mr. Spinney, meanwhile, took on the additional characters of Oscar the Grouch, Shivers the Penguin and Bruno the Trashman."
The puppet was also used as Zero, and has since made appearances as a regular penguin (including Elmo's Christmas Countdown, and in the Episode 4172 song "Six Penguins in my Shirt") and was used as Georges in 5, Rue Sésame.