It's the Great Pumpkin, Charlie Brown was originated in 1966 and is a classic to all children. It usually airs on TV them same week of Halloween and is one of my favorite old time classics.
The movie is about Linus who waits in the pumkin patch for the elusive Halloween symbol to appear. No one believes in the Great Pumpkin and calls him fake or not real.
The movie is written by Chuck Warner and is the third in the Charlie Brown series and the first halloween special. The movie won 3 Primetime awards including Outstanding Children's Program, Special Classifications of Individual Achievements, and Special Classifications of Individual Achievements in 1967. It aired for the first time on television on October 27th, 1966 and to this day contiues to the most popular halloween special amogst children and adults.
If you have young children, I would suggest introducing It's the Great Pumkin, Charlie Brown to them. They will certainly enjoy it.