Survival is a very common theme. The characters who get eaten usually have to figure out a way to stay alive inside the dragon, whether it's by finding something to eat themselves or avoiding the dragon's internal defenses.
One interesting 'getting eaten by dragon' fanfiction is 'The Dragon's Maw' which tells a story from the perspective of a character who is accidentally swallowed by a dragon. It has a unique take on the concept as the character tries to survive inside the dragon's belly.
In some dragon fanfictions, a character might be eaten by a dragon as a sacrifice. However, the dragon's digestive system has some sort of magical property that gives the character new powers or abilities. This then leads to a journey of self - discovery as the character figures out how to use these new powers in the dragon - filled world.
Once upon a time, there was a girl who wandered into a dragon's lair. The dragon, seeing the girl as an intruder, opened its huge jaws and swallowed her whole. The girl found herself in the dark and slimy interior of the dragon's belly, struggling to find a way out. But unfortunately, she couldn't escape and became the dragon's meal.
Survival is a very common theme. The character who is eaten has to find a way to stay alive in the dragon's belly. Another theme could be redemption. Maybe the dragon is a bad creature, but through the experience of having a person inside, it changes for the better.
I'm not sure if there is an exact 'Astrid eaten by dragon' vore fanfic available. There are many fanfics out there, but vore is a rather niche and often disturbing genre. It might be difficult to find such a specific one.
Fear is a big theme in these stories. The idea of a dragon eating a girl instills fear in the listeners or readers. It also has a theme of the unknown. Dragons are often mysterious creatures, and their actions, like eating a girl, are part of that mystery. And sometimes there is a theme of sacrifice, where the girl is sacrificed to the dragon for some reason, like to save the village.
I'm not sure which specific 'girl eaten by dragon story' you mean. There are various such stories in different mythologies or fictional works. For example, in some European dragon legends, dragons are often depicted as fierce and might eat humans, including girls. But without more context, it's hard to tell the exact story.
There was a time when some girls went camping near a lake. In the morning, they woke up to find ducks swimming near the shore and eating the small plants in the water. The girls watched as the ducks seemed to be slowly encroaching on their little camping area, just like in a story of 'getting eaten out' of their peaceful spot, but it was more of an endearing encounter.