There might be a dreamer as the main character. And perhaps in the dreams, there are different entities that act as guides or obstacles. For example, in one dream, there could be a wise old owl that gives advice, and in another, a tricky fox that tries to mislead the dreamer. So, the main character is the one having the dreams, and the others are within the dreamscapes.
As I don't know the actual story, I can't say for sure. But common elements in a story about dreams could be the dreamers themselves, the content of the dreams, and the actions or decisions they make because of the dreams.
The main characters are, of course, the three little princesses.
Obviously, the three little birds are the main characters.
The main characters are obviously the three little ducklings.
The main characters are the three little owls, of course.
The three little bears are clearly the main characters. There's the first bear who built his house of straw, the second bear who used sticks, and the third bear who built with bricks. And then there's the antagonist, the big bad wolf who tries to destroy their houses. These characters drive the whole story forward with their interactions.
The 'Three Little Mice Story' has as its main characters the three little mice. These three mice are the ones who drive the story forward. They are the ones who experience the events, face the challenges, and grow throughout the story. While there could be other animals in the story, such as a sly fox or a kind-hearted rabbit that they interact with, the three mice are at the center of it all.
The three little birds are the main characters, of course.
In the 'Three Little Fairies Story', the primary characters are the three fairies. Each fairy might have its own distinct features or abilities that make them important in the story. For instance, one could be the leader, while the others follow her lead in different ways.
The main characters are the three little trees. These trees are the focus of the story from start to finish. They start out as young, hopeful trees with big dreams. One dreams of holding treasures, another of sailing the seas as a ship, and the third of staying tall on the mountaintop. As the story progresses, they experience various events together, like being cut down and transformed, all while remaining the central elements of the narrative.