The costumes of the Hamelin worthies are exaggerated and highly theatrical, and make it clear that Demy’s middle ages are defiantly non-naturalistic – a land of fable rather than historical verisimilitude. They are also buffoonish outfits, casting the figures of authority who wear them as grotesques, caricatures of their own warped desires and ambitions. The Burgermeister and his wife’s social aspirations are displayed in the absurd extravagance of the hats they struggle to keep aloft during the tactical marriage of their young daughter to the slimy Franz, the Baron’s son (a mercenary wedding of new money and bankrupt aristocracy). 
Diana Dors (as Frau Poppendick, the wife) in particular carries spectacularly over-the-top headgear throughout, which she manages to keep admirably well-balanced. The portable marquee which tents her features with such ostentatious modesty early on could be seen as a satire on Hollywood medievalism, with its queens and princesses in conical turret bonnets trailing wafty clouds of gauze. The Baron has a spritish, tapering cap which looks like it's been soaked in algae, or is some fungal growth sprouting from his pate. His bullying son Franz has rolls of green cloth layered in foppish folds atop his floppy, patrician mop. 
The bishop has his papal hood rising in a mitred, scarlet shield, but his face is also shrouded in a nunnish wimple. These fools’ caps are designed to conceal and disguise, or connote status, but only serve to emphasise the wearers’ vanity, pretension or madness. The players, on the other hand, have loose tunics which hide nothing, and Melius, the alchemist who is the town’s figure of learning and reason, dresses in a simple and noble robe.