Peter Yarrow (born May 31, 1938) is an American singer who found fame with the 1960s folk music trio Peter, Paul and Mary.Yarrow co-wrote (with Leonard Lipton) one of the group's most famous songs, Puff, the Magic Dragon. He is also a political activist and has lent his support to causes that range from opposition to the Vietnam War to the creation of Operation Respect, an organization that promotes tolerance and civility in schools.