White text on a red circle with an outer white edge and then an outer blue edge
Peanuts characters from the PEANUTS comic strip by Charles M. Schultz copyright 1950 by United Feature Syndicate Inc.
In Charles Schultz' Peanuts comic strip, the Red Baron (based on the real World War I fighter pilot) was a main antagonist of Snoopy's imaginary adventures. First introduced in October 1965, the feud between Snoopy and the Red Baron was popular with audiences and was featured in comics, TV specials, and inspired the song “Snoopy vs. the Red Baron” by The Royal Guardsmen in 1966. The pinback is from the 1960s during the Red Baron's initial popularity, which coincided with large scale advertising of Snoopy on cards, figurines, NASA gear, and buttons.
Red Baron. (n.d.). Retrieved September 5, 2015 from: http://peanuts.wikia.com/wiki/Red_Baron