It's the Pied Piper, Charlie Brown (2000)

It's the Pied Piper, Charlie Brown is the last animated special produced under the supervision of Charles M. Schulz. Based on characters from the comic strip Peanuts, it was released on September 12, 2000, seven months after the death of Charles Schulz. It's The Pied Piper also has the distinction of being the first new Peanuts special to be released to DVD.

Storyline
Based on the legend of the Pied Piper, it stars Snoopy as the title character, who tries to rid the Peanuts' gang's hometown of mice by playing his concertina, in return for a year's supply of dog food.