It's fairly common. Fans often look for more content related to their favorite shows. Since 'Attack on Titan' has a large and passionate fan base, there are a lot of fanfics available. 'Aot' fans might watch (read) these fanfics to explore different scenarios that the official story didn't cover. For example, they might want to see how a certain character would react in a different situation or what would happen if a major plot event had a different outcome.
In the 'last man on earth Karl story', Karl is the central figure. He could be an ordinary person who was thrust into this extraordinary situation of being the last human. Maybe he has certain skills or qualities that help him survive, or perhaps he has to learn quickly how to endure in this new, lonely world.
I'm not sure about the main events as I haven't read it specifically. But it may involve Fritz's journey through his urban environment, facing some sort of conflict or problem.
The story 'Fritz Bugs Out' likely continues the adventures of Fritz the Cat. Fritz is a character known for his somewhat unruly and irreverent nature. He might be exploring new parts of the city or encountering different types of people. It could be that he stumbles upon a mystery or a situation that he has to figure out how to get out of. Since Fritz is often associated with the counter - culture of the time, the story might also touch on themes like freedom, non - conformity, and the search for identity within that context.
There could be various fanfictions. Maybe some that focus on alternative endings, like ones where certain characters survive who didn't in the original. For example, a fanfiction where Erwin survives and leads the Scouts in a different way.
It could mean that a person who is a fan of 'Attack on Titan' (AOT) is reading or watching fan - created fictional works related to AOT. Maybe they are interested in seeing different interpretations or storylines that fans have come up with.
One way is to check on popular fanfiction websites. Look for ones with high ratings and a lot of reviews. For example, Archive of Our Own (AO3) has a large collection of AOT fanfictions. You can search for the most popular ones there.
I don't have enough information to determine who the author of the 'fritz short story' is. There are so many authors out there who could potentially have written a story with a character named Fritz.