This is a song that was very popular for a long while. Puff the Magic Dragon by Peter, Paul and Mary found on YouTube. Hope you too will enjoy it as much as I did, hearing it for the first time in many years.
I rather liked the pictures that go with this version rather than just watching three people singing. This is actually the very first time I had listened carefully to the words and I was saddened when I realised that Puff had lost his little friend and had withdrawn into his cave. Just shows it does pay to listen to the words.