Two obvious characters to compare would be Peter Pan and Wendy Darling. As the story opens, they are both highly imaginative children with a strong sense of adventure. For this reason, Wendy can easily relate to Peter and is able to help him find his shadow. She and her brothers, John and Michael, are able to fly with Peter to Neverland and enjoy engaging in his adventures with the Lost Boys and against the pirates. Both Wendy and Peter also have a strong sense of right and wrong. This moral sensibility allows them to be selfless in defending each other and the Lost Boys from the evil Captain Hook. Both, in their own way, like to serve others.

But while the two have much in common as the story begins, from the start, their different endings are foreshadowed. Wendy is motherly and likes to take care of people. She has a responsible, stable streak that draws Peter and the other boys to her as a maternal figure. Unlike Peter, who doesn't ever want to grow up—and who is terrified of the idea—she is able to accept her future changes.

While Wendy will never lose her imagination, it will fade as she inevitably becomes an adult, marries, and has a daughter of her own. While she will still welcome visits from Peter, she reaches a time when she can no longer fly. She explains this to Peter:

“Because I am grown up, dearest. When people grow up they forget the way.”
“Why do they forget the way?”
“Because they are no longer gay and innocent and heartless [carefree]. It is only the gay and innocent and heartless who can fly.”

Nevertheless, while Peter will stay the eternal boy, both characters retain at least some of their sense of childlike wonder.