I always felt like Chewbacca appealed more to adults than children. Peter Mayhew, the actor who portrayed the famous Wookiee, passed away a few days ago (his death was announced yesterday), at what seems the surprisingly young age of 74. There was always a sense of age in his portrayal of Chewbacca, right from Mayhew's first appearance as the character in 1977's Star Wars, a kind of weariness implied in the slight tremble of his limbs. It's no wonder Expanded Universe stories made Chewbacca hundreds of years old, the long life of a Wookiee finally confirmed canonically when Mayhew appeared as Chewbacca in the prequel, Revenge of the Sith, in 2005. This is a quality not quite replicated by Mayhew's replacement in the role since retiring, Joonas Suotamo, who played Chewbacca in The Last Jedi and Solo.
George Lucas supposedly based the character on his dog but somehow Chewbacca never seemed dog-like to me. The costume vaguely recalls Lon Chaney Jr's Wolf Man, Planet of the Apes, or even Creature from the Black Lagoon. This may be another reason I think he appealed more to older viewers than to young. He's like an old friend, no longer the main attraction but still a welcome presence, along for the ride. The 60s and 70s had a lot of fiction rethinking the roles of traditionally villainous characters, notably in books like Grendel and Interview with the Vampire. Chewbacca was part of the menagerie of Star Wars; a novel aspect of the film that advanced the idea to its next stage--now the aliens and monsters were just common sights, fellow citizens. Yet the seven foot tall "walking carpet" could never just fade into a patchwork.
I met Mayhew briefly in 2010, at Comic Con. He seemed a very kind, patient man.