One of the most famous examples of a dynamic character is Harry Potter, though most major protagonists as well as many supporting characters are considered dynamic characters.
A dynamic character is simply a character who undergoes some sort of change over the course of the story. Typically, dynamic characters are considered a crucial element in the construction of a good story, as it is very difficult for writers to present static characters with whom readers can sympathize. In the beginning of the "Harry Potter" series, for example, Harry is a young boy who does not even know he is a wizard. He matures enough to overcome his fear of death and face his nemesis Voldemort. Voldemort, on the other hand, has a single goal from beginning to end: to be the most powerful wizard in the world and use that power for evil. Voldemort, therefore, is an example of a static character.