It is no secret that the Eternals are some of the oldest beings in the Marvel Universe. Not surprisingly, across the course of human history, the Eternals have inspired a number of humanity's most enduring achievements. Present from the very beginnings of civilization, through the course of several great empires, the Eternals have been behind everything from the discovery of fire and writing, to even the invention of Peter Pan.
Created in 1976 by Jack Kirby, the Eternals have occupied both a distinctly cosmic and earthly corner of Marvel lore. Each about a million years old with varying abilities unique to each of them, the Eternals were created by the Celestials to help guide the development of humanity since its very inception.
A member of the team, Sprite, revealed that he was the inspiration for J.M. Barrie's iconic character in 1901 in Neil Gaiman's Eternals #4 (pencils by John Romita Jr., inks by Danny Miki and Tom Palmer, with Tim Townsend, colors by Matt Hollingsworth, and letters by Todd Klein). Despite being as old as the rest of the Eternals, Sprite has been in the body of an eleven year-old almost his whole life. While it is never explained how exactly Sprite came across the Scottish playwright in 1901, Sprite stated that, at the time, he was working through his existential angst with being trapped in the body of a child by "show[ing] off" to humans.
Sprite being the inspiration for Peter Pan evidences a common pattern in the Eternals' interactions with humans, where members of the team achieve a type of mythological status due to their extraordinary abilities. For instance, the Eternal Makkari was the inspiration for the Ancient Egyptian god, Thoth, due to his introduction of hieroglyphics to them. While Peter Pan is not a mythological figure in the conventional sense, his literary and cultural impact is undeniable, providing not only a moral cautionary tale, but also a framework to tackle the painful truths of growing up. In fact, it's likely that Sprite was following the Eternals' usual pattern of inspiring humans - it's just that what founded myths in ancient cultures is the stuff of fiction in more advanced societies.
While Sprite may not have spearheaded the foundations of civilization for humanity like some of the other Eternals, it is clear that even his most frivolous interactions with humans led to major cultural and creative developments. Though he often wondered why the Celestials had originally chosen one member of the team to remain a child forever, his mischievous actions and personality suggest that the Celestials saw value in inspiring humanity with an eternal childish sensibility. Though Sprite eventually turned on his fellow immortals, showing a malicious nature quite different from Peter Pan, he's still an example of how the Eternals have proved to be an endless well of inspiration for all of humanity.