That film is only from 2006. See the 1996 book The Longest Shadow: In the Aftermath of the Holocaust:
It is enough to show that they[ Leon Daudet and others] sought to project an image of the Jew as, in Richard Wagner's words, a 'plastic demon of decadence': that is, as the very principle of the non-solid, of what is essentially groundless, rootless, shape-shifting...
The quote from Richard Wagner refers to his writing "Erkenne dich selbst [Know Thyself]" in Bayreuther Blatter February-March 1881, and according to the 1897 English translation compellation Richard Wagner's Prose, vol. IV, Religion and Art, the exact quote is:
Thus the Jew has need to neither think nor chatter, not even to calculate, for the hardest calculation lies all cut and dried for him in an instinct shut against all ideality. A wonderful, unparalleled phenomenon : the plastic daemon of man's downfall in triumphant surety
In German, the quote is "plastischen Dämon des Verfalls der Menschheit".
Keep in mind that the meaning of "plastic" in the 1880s was:
Having the power to form a mass of matter: capable of being molded or modeled
There is also a copy of a 1910 comic strip drawing showing a Jew shape-shifting to become Richard Wagner in the chapter "The Plastic Demon" in The Wagner Clan: The Saga of Germany's Most Illustrious and Infamous Family (see page 83).
Even earlier and more literally there is the 1804 Universal History, Ancient and Modern, Volume XIII which refers to people in Ethiopia
who firmly believe that these animals are Falasha, or Jews, from the neighbouring mountains, transformed by magick, and come to eat human flesh in safety
The 1799 The Aurora: or the Dawn of the Genuine Truth, volume 1 at page 198, also discusses people believing that hyenas are actually Jews who have been "transformed by magic".
These beliefs that Jews can magically transform into hyenas were reported by James Bruce who visited Ethiopia and published the information in Travels to Discover the Source of the Nile, In the Years 1768, 1769, 1770, 1771, 1772 and 1773. Bruce's publication has been criticized as inaccurate generally.