One popular theme is alternative universes. Fans like to imagine what would happen if the events of the show took place in a different setting or with different character relationships. For example, Zim being accepted on Earth or Dib being an alien instead.
You can try fanfiction websites like FanFiction.net or Archive of Our Own. There are often a lot of fan-written stories about 'Invader Zim' on these platforms. Just search for 'Invader Zim' in the search bar and you'll be presented with a variety of fanfictions.
One popular theme is the relationship between Zim and Dib. Writers often explore their rivalry in different ways, like what would happen if they were forced to work together. Another common theme is the exploration of Zim's alien culture and how it clashes with Earth's. It's interesting to see how different authors handle these cultural differences.
Often, there's a theme of self - discovery. As Female Zim is a different take on the character, she might be on a journey to figure out who she is in this new form. Also, the theme of adaptation is common. Just like in the original where Zim has to adapt to Earth, Female Zim may have her own unique ways of adapting, whether it's to Earth's environment or to the reactions of the other characters around her. And there's also the theme of power. How does being female change Zim's perception and use of power? This is something that many fanfictions like to play with.
You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). These platforms usually have a large collection of fan - made stories related to Invader Zim.
The dark fanfiction may also explore themes that the original series only hinted at or avoided. Such as the true nature of the Irken Empire in a more sinister way. It might show how Zim's loyalty to his home planet is more complex and disturbing, while the original series focused more on his individual antics on Earth.
The appeal of 'Invader Zim Gaz x Zim' fanfiction lies in the contrast between the two characters. Gaz is this tough, no - nonsense girl, while Zim is this bumbling alien. When they are paired in fanfiction, it creates a really interesting dynamic that fans love to explore.
A really interesting 'Invader Zim female Zim fanfiction' is 'Zim as a Girl: The Alter Ego'. This story plays around with the idea of Zim having a female alter ego. It's fascinating to see how the other characters react to this new version of Zim. Additionally, 'Female Zim in the Human World' is a great read. It focuses on how Female Zim adapts to human society, with some really funny moments like her trying to understand human fashion and social norms.