I thought it was a play on "pustefix" which is the name of a German bear that is on these bubbles: https://www.google.com/search?q=german+bubbles+bear&rlz=1C1C

I thought it was a play on "pustefix" which is the name of a German bear that is on these bubbles: https://www.google.com/search?q=german+bubbles+bear&rlz=1C1CHBF_enUS901US901&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjg8d28oOn2AhU1CjQIHbQUCh8Q_AUoAXoECAIQAw&biw=1656&bih=787&dpr=1.16 https://www.google.com/search?q=german+bubbles+bear&rlz=1C1C...