- "He won't do it again"
- ―Arnie Cunningham
Arnold "Arnie" Cunningham is the school nerd in the novel Christine and its film adaption. He starts out as one of the novel’s three protagonists, but later becomes the secondary antagonist.
The novel opens with a line of dialogue from Arnie, pleading with his best (and essentially only) friend, Dennis Guilder, to back up so Arnie can see the yard they just passed. From the very first time he speaks of the 1958 Plymouth Fury for sale in Roland D. LeBay's unkempt yard, Arnie calls the car "her." Dennis rightly recognizes that it was love at first sight for Arnie. The shy and myopic teenager eagerly goes to examine the decaying Plymouth up close, ignoring Dennis' obvious dismay at the appallingly-poor state of the car. When Roland LeBay comes outside to see what the two boys are up to, Arnie immediately declares his intent to buy the car. LeBay brushes Dennis off and Arnie soon negotiates his buying Christine for $250. Buying the car starts a fight with both his parents that runs the entire length of the novel, effectively creating open warfare in the formerly-uneventful Cunningham household.
Dennis reflects that Arnie's parents are nowhere near as open-minded or fair as they pride themselves to be. They are lifelong liberal activists, but have pretty much managed Arnie's entire life. Arnie, who used to accept this without question, suddenly begins a fierce battle against any decision of theirs that he dislikes. At school, he uses Roland LeBay's word, "shitter” when Buddy Repperton corners him outside. Long an easy target for bullies, Arnie fearlessly opposes Repperton and even does surprisingly well alongside Dennis during the ensuing fight. He remains best friends with Dennis, but starts to spend more and more time over at Darnell's working on Christine. Eventually, when the beautiful Leigh Cabot transfers to Libertyville High, Arnie stuns the entire student body by bringing her to the next football game. His acne, formerly so bad that he was called "Pizzaface" by almost everyone, begins to clear up and then vanishes entirely. Arnie and Dennis have their first serious argument when the former catches the latter looking at Christine in the school parking lot, noting the barely-roadworthy state of the car. Arnie also refuses to discuss his new business relationship with Will Darnell, in which Arnie gets free access to the garage and is paid well for "errands" i.e. picking up parts and cars of dubious origin and bringing them to the garage.
Over time, Arnie begins displaying personality traits, mannerisms, and behavior he had never shown before. While his newfound good looks and confidence win him a relationship with Leigh Cabot, he persists in placing Christine first in his life. Arnie briefly reconnects with his father, who is more sympathetic to his side than Regina is, and even agrees to park Christine in a rented space at the local airport. Sandy Galton, one of Buddy Repperton's crew, immediately tells Buddy about this, and the Repperton gang proceed to destroy the car. Distraught and furious, Arnie shoves everyone and everything aside as he tries to rebuild Christine. Slowly, inexplicably, he begins to make real progress. Arnie is more isolated and alone than ever as he pours all his time and money into repairing Christine and running errands for Darnell.
Dennis Guilder, who sees little of Arnie after his hospitalization due to a serious injury in a football game, starts to realize that Arnie is acting less and less like himself and more and more like Roland LeBay, even wearing a backbrace like LeBay did, speaking the way he did, and making out-of-date popular culture references. Arnie briefly resurfaces as himself in a conversation with Dennis, but LeBay overpowers him. Dennis baits LeBay into sending Christine to Darnell's for a showdown while Arnie is out of town with his parents. During the fight at the garage, LeBay gives up on Christine as she is run down by Petunia (a rented septic tanker) and tries to possess Arnie. Arnie fights back, but his parents' Volvo crashes and all three Cunninghams are killed. Arnie briefly appears while Dennis is in the hospital again, wearing cracked glasses. He tells Dennis that "everything's cool", but Dennis laments his failure to save Arnie for years to come.
In the film, Arnie is played by Keith Gordon and is largely identical in behavior to his character from the novel. In this version, Arnie buys Christine from George LeBay, as Roland had died six weeks before the start of the film. Arnie argues bitterly with his parents over the Plymouth and takes her to the auto repair garage Will Darnell owns. Darnell is furious at the foul exhaust the car spews everywhere, but ultimately lets the car stay. Soon, Dennis learns that LeBay's wife died in Christine of Carbon Monoxide Poisoning. Over time, Arnie falls increasingly under Christine's influence, acting, speaking and dressing differently from before. After Buddy and Co. trash her, he takes his anger out on Leigh Cabot, essentially abandoning her for Christine. At an empty Darnell's, Arnie swears revenge on the people who trashed Christine and vows to repair her. Christine begins to repair herself as he witnesses, and after Arnie steps back and says, "Okay, show me,", she shines her headlights and rebuilds herself in front of him. Will Darnell is among those curious about Arnie's miraculous rebuilding of Christine, and, overcome by curiousity, sits down behind her wheel one night when she parks in her space in the garage after killing Buddy while on fire, allowing Christine to kill him by squeezing him between the bench seat and the steering wheel. Arnie has no direct involvement in Darnell's murder, or that of Buddy Repperton or Moochie Welch, and he has a convenient alibi to give Detective Rudolph Junkins of the Pennyslvania State Police each time. Eventually, Arnie is completely isolated and alone, and Dennis lures him and Christine to Darnell's for a showdown. Arnie surprises Dennis and Leigh by arriving earlier; he attempts to run them both down and nearly succeeds. During the fight, Arnie crashes and flies through the windshield, dying soon after from a glass shard impaled through his stomach. Rudolph Junkins assures Dennis and Leigh that they did all that they could, but Dennis laments, "A real hero would've saved Arnie." Arnie's parents are still alive at the end in the film adaptation.
Personally: In both the novel and film, Arnie, at first, was a shy, kind-hearted and caring person who cared deeply about his family and friends, but after buying Christine and getting under her influence, he changes and becomes cruel, prideful, assertive and aggressive, capable of killing people, including his own family and friends if they dare hurt or get rid of Christine.
- He along with Helen Shyres and Teddy Duchamp are one of the main Stephen King characters to have round glasses.
- Arnie's father was originally going to be the one who flew through Christine's windshield in the fight at Darnell's garage, as a deleted scene shows.
- In the book, Arnie is influenced by LeBay's spirit, which is the source of Christine's power. In the film, Christine herself is simply "evil" and Arnie is gradually possessed by her instead.