One possible theme could be a sense of betrayal. For example, if Bilbo feels betrayed by his companions during the adventure, it could lead to his anger. This could be related to issues like sharing of the treasure or decisions made during their journey.
I'm not sure of a specific 'angry bilbo baggins fanfic' off the top of my head. But you can try looking on fanfic websites like Archive of Our Own. There might be some stories there that explore an angry Bilbo Baggins in various scenarios, such as during his adventures when he's faced with difficult challenges or when he has disputes with other characters in Middle - earth.
Common themes in 'female Bilbo Baggins fanfic' include empowerment. A female Bilbo can be shown as breaking barriers in a world full of challenges. Also, there is often the theme of adaptation. How does she adapt to the quest and the company of dwarves? It's not just about being female, but also about how that changes the story's flow. There might be fics where she has to prove herself more because of her gender, which is an interesting take on the classic story.
A major theme in these fanfictions is the relationship changes. His friends, like the dwarves or Gandalf, might react differently to him as a vampire. Also, the theme of temptation is present. The urge to drink blood and how Bilbo resists or succumbs to it is often explored in detail. For example, in some stories, he has to find alternative ways to satisfy his vampiric thirst without harming the innocent. This adds a layer of complexity to his character and the story as a whole.
Self - discovery is also a theme. Just as Bilbo discovers his own courage and capabilities during his adventures, the OC may also be on a journey of self - discovery. They could be learning about their own powers, their place in the world, or their true identities, all while being influenced by their interactions with Bilbo.
The theme of discovery is also prevalent. Many young Bilbo Baggins fanfictions depict his discovery of new places, cultures, and ideas. This could be his first encounters with elves or dwarves, and how these meetings broadened his horizons and made him question the small - mindedness of some in the Shire.
One common theme is the exploration of gender roles. Since Bilbo is male in the original, making her female in fanfiction allows for a new look at how she would handle situations in a world with traditional gender expectations. For example, how a female Bilbo would be treated by male dwarves during their journey.
Maybe the cat spirit animal has the ability to communicate with Bilbo in his dreams. It imparts wisdom about the journey ahead, like which paths to take and which treasures are truly worth seeking. The cat could be a connection to an ancient magic in Middle - earth that only Bilbo, as a hobbit with a special bond to this spirit animal, can access.
The plot might involve Bilbo having to face new and more dangerous foes while on his quest for the great treasure. He could be joined by some old friends or make new allies along the way. For example, he might encounter a group of dwarves who have heard rumors of the treasure and team up with them. They could journey through uncharted lands, facing challenges like treacherous terrains, dark magic, and ancient curses. Bilbo's wits and the experience he gained from his previous adventures would be put to the test as they strive to find and claim the great treasure.
One popular 'bilbo baggins cat fanfic' might be the one where Bilbo discovers a magical cat in Middle - earth. The cat has the ability to communicate with him and they go on adventures together, exploring hidden caves and encountering strange creatures.
One popular theme is changing the past. In many fanfictions, Bilbo tries to alter certain events in Middle - earth's history through time travel. Another theme is exploration. He travels to different times and discovers new places and cultures. For example, he might visit the ancient dwarven kingdoms at their peak.