As of the latest chapters, Big Mom did die. The circumstances surrounding her death were quite complex and tied to a series of intense battles and plot developments.
In One Piece Big Mom OC fanfiction, a frequent theme is survival. Big Mom's world can be a dangerous place, and OCs have to figure out how to stay alive. There's also the theme of discovery. The OC might be exploring new parts of Big Mom's territory or uncovering secrets about her past. And the theme of friendship can be found too. The OC could form bonds with other characters in Big Mom's crew or even with those who oppose Big Mom. For instance, an OC might become friends with a character who wants to escape Big Mom's rule.
In these fanfics, the relationship with Big Mom is a central element. It can range from total adoration to complete rebellion. The OC son's backstory also matters a great deal. Maybe he was an outcast among Big Mom's children, or he had a special upbringing that sets him apart. Additionally, the inclusion of other One Piece characters is key. For example, how the OC son interacts with Luffy and his crew, or how he fares against other powerful pirates in the series. All these elements combined create a rich and engaging 'One Piece Big Mom OC Son Fanfic'.
One popular One Piece Big Mom OC fanfiction is 'The New Crewmate'. It focuses on an original character who somehow becomes part of Big Mom's crew. The story has interesting plot twists as the OC tries to navigate the complex politics and power dynamics within the crew. Another great one is 'Big Mom's Secret Ally'. In this, the OC has a hidden agenda and forms an unexpected alliance with Big Mom. It's full of action and mystery.
Chopper is very much alive in the One Piece manga. The creators haven't written his death into the story. He's an integral part of the crew and their journey continues without that tragic event.