What was this children's movie with a horrific ending?

I don’t remember much at all, but it was a 2D cartoon that probably was straight to video. I think it may of had something to do with a circus and the heroes facing their fear.

What I do remember clearly is the end of the movie consisted of protagonists walking away from the villain, who was an emaciated, elderly man in a top hat with a screw for one eye. After the heroes leave, he starts to panic about being alone with the crows, who descend on him, cover every inch of his body for a few moments before fluttering away, leaving the screw for his eye to clatter to the floor.

Yes, even as a kid that ending scared the crap out of me. The rest of the movie was forgettable.