Help, I Shrunk My Parents

Help, I Shrunk My... German Movie Series
Felix's school is haunted again, only this time it's not the benevolent spirit of school founder Otto Leonhard and the nuisance he caused, but the once hated and long-since dead Director Hulda Stingbeard. A coincidence causes the former shrunken and skeletonized school principle to rise again, leading to chaos...
Small parents. Big trouble.