Since I don't know the exact 'frog graphic novel', it's hard to say. But most likely the frog itself is a main character. There could also be other animals like a wise old turtle or a friendly squirrel that help or interact with the frog.
In a 'frog graphic novel', if it's a story about the frog's life in a natural setting, the main characters could be the frog, of course. And perhaps there are some bird friends who warn the frog about approaching predators. There might also be a group of fellow frogs that the main frog character is part of, and they all have different personalities and roles within the group. There could even be a sneaky snake character that is always trying to catch the frog, adding some conflict to the story.
Since it's a toon graphic novel, there might be some zany side characters. There could be a mischievous little imp that tries to interfere with the discovery of the stone frog's secret. There might also be a kind - hearted animal friend that helps the main character in their quest. And then there's the stone frog, which could be a mysterious and alluring character that draws in all the others in the story.
The main characters are usually the frog who later turns into a prince and the princess.
The main character is obviously the frog princess herself. There might also be a prince, perhaps a wizard or witch who cast the spell on her, and some friendly animals that help her on her journey.
The main characters are the scorpion and the frog.
As I don't know the story well, I assume the main characters would be the frog parents and their baby frogs.
The little frog is definitely one of the main characters. There might also be other animals like a big fish if the frog lives near a pond, or a bird that the frog interacts with.
The two main characters are the boy and the frog. The boy is likely a curious or kind - hearted human, while the frog is an amphibian that has some sort of interaction with the boy, like they might go on an adventure together or help each other out.
Tiana is a main character. She is a hard - working woman with a big dream of opening her own restaurant.
The main characters are the princess and the frog who is actually a prince. The princess is an important character as the story revolves around her interaction with the frog.
The main characters are the scorpion and the frog.