Arnold Richard Cunningham is the main protagonist villain of Stephen King's Christine after the deaths of the Repperton gang including the local teens' leader named Buddy Repperton himself one by one of Christine, the other two in the former role being Dennis Guilder and Leigh Cabot. He was portrayed by Keith Gordon.
In the book, Arnold is myopic (near-sighted) and has only one friend, the popular high school jock named Dennis Guilder, and both of them are students at Libertyville High in Libertyville, Pennsylvania.
He notices Christine and urges Dennis to go back so he can look at it. After he wants to buy it, he hastily writes Roland LeBay, a cheque. After his parents refuse to let him keep the car at the house he is forced to store it at a Do-It-Yourself garage run by Will Darnell and later the airport.
Later he restores the car to its natural beauty but the more time he spends with Christine the more she takes over his mind. Now obsessed with the car, his personality changes and he no longer wears his glasses as if his vision has improved greatly and he becomes humorless and prideful but also assertive and cruel. After Leigh Cabot becomes his girlfriend, Arnold gets into a fight with Buddy Repperton which results in Repperton being suspended.
Later on when Buddy and his gang trash Christine, Arnold is shocked to discover all the hard work he put into restoring the car has been ruined and is determined to restore her to normality. Later on, even before or after the deaths of his parents Regina and Richard and Michael Cunningham, Arnold strains his back and starts wearing a back brace and later on Dennis and Arnold have an argument in which he goes against his friends and in the process is killed in a motorway accident.
n the film, Arnold is best friends with Dennis Guilder and a student at Rockbridge High in Rockbridge, California. On September 12, 1978, he purchases Christine from Mr. George LeBay, brother of the late Roland LeBay, who was Christine's previous owner. After an argument with his parents, Arnold was forced to keep it at the Darnell's Do-It-Yourself Garage run by William "Will" Darnell. Soon Dennis learns that LeBay's wife named Rita (Veronica in the novel with their daughter named Rita) died in Christine of carbon monoxide poisoning after the recent death of their 5-year old daughter, though she wanted to die the same suicidal way her careless husband died because of his crazy obsession with Christine.
Later on Arnold falls under Christine's influence and after Buddy and his men trash her he takes his anger out on Leigh, his girlfriend. After his parents tell him they will buy him a new car since now his current vehicle has been vandalized by Repperton and his men, he fights verbally and physically with his parents and even goes as far as to strangle his own father. He swore revenge on the people who trashed Christine and is determined to repair her, but she repairs herself in front of him as Christine shows her regenerative powers to her new "lover".
Arnold then goes against his own two friends Dennis and Leigh and attacks them at Darnell's garage that night but is killed after being ejected through the windshield and being impaled on a hard shard of glass.