This sound comes from Kaamelott, the French comedy series created by and starring Alexandre Astier. The show became widely quoted online thanks to its dense writing, deadpan arguments, and memorable insult-like lines, and “hérétique démon” fits that instantly recognizable style. Short Kaamelott audio clips spread especially well in French-speaking meme culture, where they are reused as reaction sounds for absurd takes, petty disputes, and dramatic callouts. The clip remains popular because even people who do not know the exact episode still recognize the series' medieval-comic tone.