It's about a dog named Old Yeller. In the story, Old Yeller goes on various adventures. He might face challenges like dealing with wild animals and protecting his family. It shows the bond between the dog and the people around him.
The main character is surely Old Yeller, the dog. There might also be the family members that Old Yeller is associated with, like the boy who might be his owner or caretaker.
The climax is when Old Yeller has to fight off a rabid wolf to protect the family, but gets bitten and has to be put down by the boy who loves him. It's a heartbreaking and intense moment.