I'm pretty sure I saw this movie on Cartoon Network back a long while ago. My memory may be fuzy but I remember something like this is was an 80s-90s era animated film based on the pied piper that's like set in modern times where the rats come back to the/a city and turn everything to gold, and a bunch of kids have to find the original pied piper and get him to help.
I have searched every where to find a shred of proof of this movie's mere existence, but have found nothing. Does anyone know what this movie is, or at least that it existed?

If it's any help the movie had a kind of Don Bluth-y feel to it...