In most cases, no. American fiction is focused on the main narrative and doesn't commonly incorporate post-credit scenes. However, there might be some rare exceptions in experimental or unconventional works.
A post - credit scene scary story might involve a cursed object. In the main movie, the object seems harmless, but in the post - credit, it starts to glow and strange noises come from it. It then causes chaos in the empty theater where it was left. Also, there could be a post - credit scene where a character finds a diary that tells of a horrible past. As they read it, shadowy figures start to appear around them, and the words in the diary start to bleed, creating a truly terrifying moment.
It can be quite important. It might set up future plotlines or introduce new characters. For instance, it could be the start of a new arc for a character like Qi'ra.
You can watch the full version of The Gorillas 4: Final Chapter in high definition on Cechi Cinemas 'website. The film was directed by Scott Waugh and starred Jason Statham, Megan Fox, and Duff Longer. The plot focused on the story of a group of experienced mercenaries, telling the story of the last gathering of the death squad, boarding a cargo ship full of nuclear bombs, and carrying out a shocking operation to prevent the nuclear bomb from exploding. Please note that you need to visit the Cech Cinemas website to view this movie.