Since we don't know the exact story, it could be the friendly shark itself as the main character. There might also be other sea animals like fish, dolphins, or turtles that interact with the shark and are important characters in the story.
The main character is surely the friendly shark. But there could be a whole host of supporting characters. If it's a story about the shark in its natural habitat, then other sea creatures like seagulls that might interact with the shark on the water's surface, or tiny shrimps that live in the same area could be part of the story. If the story has a more ecological theme, there could be a character like a coral reef that the shark and other creatures rely on, which could also be considered an important 'character' in a way.
In the 'Shark in the Dark Story', the most obvious main character would be the shark. But depending on the nature of the story, there could be other important characters too. If it's a story about the shark's journey, perhaps there could be a seagull that the shark sees flying above the water's surface during the day before it goes into the dark depths at night. Or there could be an old, wise octopus that the shark encounters in a dark cave, and they have some sort of interaction. Maybe there are also other sharks that the main shark has a relationship with, like a rival or a mate.
Since I don't know the story well, I can't say for sure. But the shark must be one of the main characters.
It's hard to say for sure, but perhaps the main characters are a couple of siblings. The older sibling might be protective of the younger one when it comes to the idea of sharks. And there could be a new kid in town who joins them in their exploration of the shark world. They all together form the main characters who drive the plot of the 'Shark Kids Story'.
Since I don't have access to the story, the main characters could be a fisherman who gets into trouble and becomes shark bait. Or it could be a group of surfers where one of them is in a situation that makes them seem like shark bait. There could also be a marine biologist in the story who is studying sharks and somehow gets too close to the sharks and becomes the so - called 'shark bait'.
Given the title 'shark girl tf story', the obvious main character is the shark girl. But there could be other supporting characters. For example, if the story is set in a coastal town, there might be fishermen who have seen strange things related to the girl. Or if it's a story about her fitting into a new world, there could be other 'creatures' or people in that world who interact with her. There could also be a mentor - like figure who helps her understand and control her new form or abilities if it involves a transformation.
I'm not sure as I haven't read this novel. So I can't tell you who the main characters are.
The 'friendly shark story' might be about a particular shark that shows friendly behavior. It could be that this shark helps other fish in some way, like guiding them away from danger or sharing food. It may also be about a shark that gets along well with divers, allowing them to swim close without any threat. It's all speculation though, as the details would be in the actual story.
I think the shark must be a main character. And perhaps there could be some people in the park as well. They would be important as they might be the ones who interact with the shark, either by trying to avoid it or being curious about it.
The main characters in 'the friendly dragon story' are likely to include the dragon, of course. There might be a group of children who find the dragon in a forest or a hidden place. One of the children could be the leader of the group, who has the courage to approach the dragon first. There could also be a villain in the story, perhaps a hunter who wants to capture the dragon for some wrong reasons, and the other characters have to protect the friendly dragon from this threat.
It's difficult to say for sure without reading the story. However, it's likely that the friendly dinosaur is one of the main characters. There may also be other dinosaurs or prehistoric creatures that play significant roles. For example, there could be an older, wiser dinosaur that guides the friendly dinosaur, or a young, curious creature that the friendly dinosaur takes under its wing. The interactions between these characters would likely be central to the story and help to illustrate the theme of friendship in the prehistoric world.