“I’m a Mog: half man, half dog. I’m my own best friend.”

That’s how Barf, John Candy’s character in the 1987 Mel Brooks comedy Spaceballs, describes himself. Sometimes parody is subtle, but sometimes it’s best performed by simply describing the thing you’re mocking in blunt terms. While the Star Wars films are beautiful and exhilarating pieces of cinema, they do spend a lot of time exploring the question of “What if your pet were also your mechanic?”

The pet-mechanic combination shows up all the time in Star Wars. Luke Skywalker flies his X-wing across the galaxy with R2-D2, who’s part beer keg, part Swiss army knife, with the personality of a cat. Occasionally they’ll meet up with the Millennium Falcon, crewed by Han Solo and Chewbacca, who, like Barf, is half man, half dog.

R2-D2 and Chewbacca became two of the most beloved characters in the series, which is a testament to how intelligently they were crafted, considering neither has ever uttered an intelligible line of dialogue. We hear only half of their conversations, and infer the rest through tone and body language, like the swaths of unsubtitled Russian in The Russians Are Coming! The Russians Are Coming! R2-D2 and C-3PO have a Bert-and-Ernie-type relationship that serves as comic relief, and both R2 and Chewie served as confessors for Luke and Han, respectively. When they’re alone on Dagobah in The Empire Strikes Back, Luke thinks out loud to R2, but for Han and Chewie, the relationship is deeper.

Solo, the most recent Star Wars film, explores the origins of that relationship. Traditionally, Chewie follows Han around not because he’s Han’s friend and employee but because Han once saved his life, and according to Wookiee tradition, Chewie owes him a life debt. Though Han does save Chewie twice early in the new film — once from Imperial imprisonment, once from falling off a train during a heist — the life debt is never mentioned out loud. Instead, Chewie follows Han because for as naive and disorganized as the young Solo is, there isn’t really a better gig immediately available. Devoid of that backstory, the relationship that Han and Chewie have in A New Hope is one in which Chewie is obligated to Han: employer-employee at best, but perhaps something more akin to servitude or, indeed, pet ownership. But Solo shows a naturally developing friendship; it’s never clear why Chewie lets Han call all the shots, but it is clear that Chewie follows Han out of his own free will, and not out of obligation.

Over the seven hours or so of the original trilogy, the Han-Chewie relationship is pretty simple. Han is clearly the leader, but there’s love and respect in both directions. It’s Chewie who arranges the original meeting between Han and Obi-Wan that sends the Falcon to Alderaan, but Han who negotiates the fare and calls the shots when the two gradually become involved with the Rebellion. When Han gets captured, Chewie joins the rescue party, and when Han volunteers for the mission to disable the shield generator on Endor’s moon, he made a point not to assume that Chewie would volunteer for the mission. “Well, it’s gonna be rough, pal,” Han says. “I didn’t want to speak for you.”

But the humor in that moment is based on the audience’s assumption that Han would never go anywhere without Chewie, and Chewie would never let Han face a dangerous enemy alone. It’s the relationship between hero and sidekick, which is all we need over a three-movie arc in which Chewbacca might be the 10th-most-important character.

The original trilogy, for Han and Chewie, is all an extension of a choice they made within moments of appearing in the story: They were supposed to take Obi-Wan, Luke, and the droids from Tatooine to Alderaan. Everything that follows until the destruction of the second Death Star is just the result for Han’s decision to stick around. But 2015’s The Force Awakens follows that relationship long after the Alderaan charter ends, and Solo picks it up long before it begins. In all, we’ve now seen Han and Chewie work together for something like 45 years of in-universe time. The hero-sidekick relationship follows certain beats. Over the course of one job, the relationship between a captain and his first mate might not be distinguishable from the relationship between a man and his dog, if the dog can also fly a spaceship, repair droids, and handle a bowcaster. Over 45 years, though, you can’t help but ask questions about the dog-man’s agency, particularly as Chewbacca exerts his own influence on the story separate from Han’s.

Chewbacca had a cameo role in Revenge of the Sith, in which he fights at the Battle of Kashyyyk and helps Yoda escape after Order 66 is issued. After Han’s death in The Force Awakens, Chewie takes Rey to Ahch-To for training with Luke, and there he bonds with the planet’s native porgs (after he kills and barbecues one of them). In Solo, we learn that Chewie is 190 years old when he meets Han, confirming the longevity of Wookiees, which had been hinted at in the Expanded Universe.

The EU, a series of Lucasfilm-licensed novels that told the story before, after, and between the first three movies, began in 1991 with Heir to the Empire, and in just a few years the dozens of constituent books had run their course. Over 20 years of in-universe time, the Rebellion had reorganized as the New Republic, retaken Coruscant, and beaten back the remnants of the Empire, including dozens of villains who became famous in their own right among Star Wars fans. Han and Leia had married and had children, and Luke had begun to rebuild the Jedi order. The original story had been completed. So in 1999, a new enemy was created: a species of terrifying and implacable extragalactic invaders called the Yuuzhan Vong, who could not be sensed through the Force.

The New Jedi Order series, as it was called, tied together dozens of characters from the films and the various EU book series, lasted 19 novels, and was written by 12 authors from 1999 to 2003. It swept the decks clear, and the way the authors showed their intent was by killing Chewbacca off at the end of the first book.

In a post–Game of Thrones world, it’s hard to imagine being shocked by the death of any character we’d once thought untouchable, but Chewbacca’s death was, in fact, shocking. The Yuuzhan Vong had caused a moon to fall down on a planet called Sernpidal, and the Millennium Falcon was aiding with the evacuation. Chewie was able to get Han and Leia’s youngest son, Anakin, onto the ship, but couldn’t get back in time to save himself.

Yet even that heroic and dramatic death blurred the line between man and dog. Was Chewbacca’s act of self-sacrifice nothing more than the same gambit J.K. Rowling opened Harry Potter and the Deathly Hallows with? That book, the last chapter in one of the few contemporary action-fantasy series to rival the popularity of Star Wars, features the death of Harry’s owl, Hedwig. A beloved character dies to show that this book isn’t messing around, but that character is a pet nonetheless.

The Star Wars universe features ape-people, rat-people, and insect-people. Slug-people run crime syndicates and squid-people command fleets of warships. And yet Chewbacca, a dog-person, is given relatively little free will — he just does whatever Han, or whoever he considers to be Han’s proxy at the moment, tells him to.

Solo is the first of the Disney Star Wars films to acknowledge that the humanity, for lack of a better word, of Wookiees and droids is a little ambiguous. The English actress Phoebe Waller-Bridge imbues L3–37, Lando’s droid, with incredible panache. Droids have been heroic, sarcastic, and stubborn throughout the Star Wars films, but L3 is the first to embrace the idea that droids are sentient beings. As L3 turns the coaxium heist on Kessel into a jailbreak, Chewbacca abandons the job briefly to fight for his fellow Wookiees. Chewie abandoning Han in a moment of danger, even for a moment, would’ve been unthinkable later in the relationship. And yet Chewie later chooses to stay with Han rather than flee with his newly liberated Wookiee friends for parts unknown. This is now a relationship, if not of equals, then of choice.

The more Chewbacca appears in these films going forward, whether it’s Episode IX or other anthology pictures, the more the people behind Star Wars are going to have to grapple with Chewie’s self-determination. As he continues to take part in the story after Han’s death in The Force Awakens, what does he want now that he’s on his own? For the first time in 40 years, Chewbacca is his own man, and for the first time, he’s being written more like a man than a dog.