Three Woodstock characters standing in a column with the top holding a red flag with black text. Image has pink background in outline around it with white background.
The yellow birds in The Peanuts comic strip by Charles M. Schulz first appeared in the 1960. Eventually the yellow birds inspired the character Woodstock, Snoopy's sidekick, who was introduced in 1968 as a consistent character. The birds chirp a language that only Snoopy can understand and are often seen with the onomatopoeia “sniff.”
Woodstock. (nd.). Peanuts by Schulz. Retrieved from https://www.peanuts.com/characters/woodstock/#