Obviously, the little rooster is one of the main characters.
The main character is the little rooster. There might be secondary characters such as the mother hen that teaches the little rooster some things, and the other young chicks that the little rooster grows up with. These characters play important roles in shaping the story around the little rooster, either by being friends, foes or mentors.
The main characters are the boy and the rooster, of course.
The main characters are the fox and the rooster, of course.
Since I don't know the exact 'black rooster story', I can't say for sure. But it might have the black rooster as the main character, and perhaps there could be other animals like hens, a sly fox, or a kind old farmer.
Regarding Rooster Teeth Animated Stories, in 'RWBY' the main characters each bring something unique. Ruby with her determination to be a Huntress, Weiss with her elegance and combat skills, Blake with her mysterious past, and Yang with her strength. In 'Red vs. Blue', Church is the central figure in the early seasons, his sarcastic and sometimes confused nature driving the story. Tucker provides a lot of the humor with his womanizing ways and Caboose is the innocent - but - dangerous type. In 'Camp Camp', David is the heart of the story, constantly trying to make the camp a positive experience for the kids while dealing with their antics.
Other than them, there could be new characters created specifically for the fanfic. These might be other pilots in training with Rooster. They could be his rivals, constantly trying to outdo him in training exercises, or they could be his allies, working together to solve problems and complete missions.
The moral could be about self - discovery. The little rooster might learn to be confident in itself and its abilities.
I don't have enough details about 'the little story' to say for sure, but it could be a child, a pet, or an old wise man.
In the chicken little characters story, the key character is Chicken Little, the one who believes the sky is falling. Another important character is Foxy Loxy, a rather sly animal. There are also other barnyard animals like Henny Penny and Ducky Lucky who are involved in Chicken Little's adventure when he spreads the word about the sky falling.
Since I don't know the exact 'big metal rooster story', it's hard to say who the main character is. But it could be the person who made the big metal rooster.
The main characters of 'little busters main story' are the boys and girls who form the Little Busters. Riki Naoe is a central character, being somewhat of a narrator in a way as we see the story through his perspective at times. Kyousuke Natsume is a charismatic figure in the group. Then there are other members like Masato Inohara and Kengo Miyazato. The female characters such as Rin Natsume also play significant roles in the story, adding different dimensions to the relationships and the overall plot.