Carnivorous plant named Adela was not a prop, but real plant (though not, of course, carnivorous). A specialist from a local university was required to take care about the plant during the filming.
In this film, Nick Carter has a signed photograph from Sherlock Holmes. While many people think of Nick Carter as the "American Sherlock Holmes", Holmes did not debut until 1887; Nick Carter preceded him, debuting in 1886.
Czechoslovakia's official submission to 51st Academy Award's Foreign Language in 1979.
Slovak actor Michal Docolomanský turned out to be unable to speak Czech without a thick Slovak accent, which in combination with character of American detective sounded particularly cringey. He was therefore completely overdubbed in the film by the cultivated voice of Frantisek Nemec. Many years later, the same actor overdubbed Docolomanský in Perníková vez (2002) as well.
The author of the animation sequences of the carnivorous plant Adela, as well as some special props (a flower with a giant eyeball, Nick Carter gadgets) was the surrealist artist and filmmaker Jan Svankmajer.