Copper

Copper is a Coonhound/Bloodhound mix and the titular deuteragonist in Disney's 1981 feature film The Fox and the Hound and its 2006 midquel. He becomes best friends with Tod the fox, despite the two being natural enemies. He was voiced by both Corey Feldman and Harrison Fahn (the latter voiced him in the midquel) as a puppy, and by Kurt Russell as an adult.

Background
Copper is loosely based on a hound dog with the same name that appeared in the novel The Fox and the Hound by Daniel P. Mannix. Besides the major changes between the book and the film, the original Copper was an older dog threatened by a younger dog named Chief (the film seemingly switches the two roles.)

In the film, Copper is a Coonhound/Bloodhound mix. His body is light-brown with dark brown ears and a dark brown spot on his back. He also has a white muzzle and belly, and four white paws. As an adult, he wears a blue collar.

Personality
As a puppy, Copper is fairly curious. He has an excellent sense of smell, which made prone to wandering off, following various scents. One of these instances led to him befriending Tod, being unaware that the two were natural enemies. However, he could be slightly cautious, especially around his owner and the older Chief.

As an adult, he is much more serious, having been trained as a hunting dog. However, he does not initially go for Chief's theory that a hunting dog must be nasty, preferring to simply track and smell out game. His training leads him to break off his relationship with Tod. However, he spares his friend out of past friendship until Chief is injured in an accident, at which time he becomes focused on revenge. However, their friendship would be rekindled, in a distant manner, when Tod saved him and his master from a rampaging bear. Copper would later repay his friend brave efforts by keeping his still mad boss from shooting Tod.

The Fox and the Hound
He is introduced as a cute small puppy that Amos Slade had recently obtained. Amos Slade intends to train the puppy as a hunting dog, and instructs his older dog Chief to look after him. One day, Copper wanders off, intent on following an unusual scent and ends up meeting Tod the fox kit. The two play together and become good friends, not realizing the two are natural enemies. Copper must keep his friendship secret, and often sneaks off to play with Tod. Copper's owner, Amos, is an avid hunter while Chief is a trained hunting dog, and the two would certainly kill Tod if given the chance. Eventually, Amos grows tired of Copper running off and ties the puppy to his doghouse to shut him up and conk him out. Tod comes over to see why Copper isn't coming to play. When he sees that Copper is tied up, the fox kit attempts to play there, but Copper worries that Chief will awaken. Chief awakens after smelling Tod, and chases him across the woods with his house still attached. Amos chases after them trying to shoot Tod, believing the fox cub was harassing his chickens. Much to Copper's relief, Tod is able to escape successfully.

Soon after, Copper is taken on a long hunting trip with Slade and Chief. During the winter, Copper grows into an adult and becomes a skilled hunting dog. When spring arrives, Copper returns, having helped Amos obtain a large amount of animal skins. That night, an adult Tod comes over to see Copper, but Copper tells Tod that they can no longer continue their friendship. Copper is now a hunting dog, and Tod is a fox. Suddenly, Chief and Amos catch Tod on their property and Copper is forced to track his former friend. Copper doesn't want to see Tod killed, and so he lets the fox get away. However, Chief notices Tod, and chases him onto a railroad bridge. When a train comes, Tod is able to escape, but Chief is badly injured. Copper immediately regrets letting Tod go, and vows revenge.

When Amos and Copper realize that Tod's owner, Widow Tweed has released Tod into the game preserve, the two decide it is the perfect opportunity to get revenge. They are able to track Tod to a den, where the he is staying with Vixey, a young female vixen. Amos sets traps along their path, but the two foxes are able to avoid them. Setting a fire near one den entrance, Copper and Amos wait at the other entrance. Both are shocked when Tod is able to escape through the flames and avoid them, and Copper gives chase.Copper and Amos chase the foxes up the cliff when Copper picks up a new scent and a look of horror dawns on his face. Amos catches up to Copper when suddenly, a huge grizzly bear appears from the bushes. While trying to escape from the bear, Amos is caught into one of his own traps, and so Copper tries to attack the bear and defend his owner. Copper is badly injured and no match for the bear, and Tod arrives to defend his former friend. Tod is able to defeat the bear, but is immensely hurt as well. As Copper approaches the weak and exhausted Tod, he is amazed that the very fox he tried to kill saved his life, and now feels genuinely remorseful for what he's done to him. When Amos arrives to kill Tod, Copper stands in the way of the gun, refusing to move away, and Amos eventually lowers his gun,  sparing Tod's life. Copper returns home with Amos, fondly remembering his friendship with Tod.

The Fox and the Hound 2
Copper is one of the main characters of the sequel, which takes place prior to Copper going hunting with Amos Slade. In the film, Copper feels he is unable to do a lot of things right, whilst Tod tries to list things he can do, however realizes that at the time of the Movie, Copper wasn't even House Trained yet. He and Tod later slip away to a country fair, where they encounter a group of stray dogs who formed a band known as the "The Singin' Strays". They find out that the band is preparing to perform, and that a talent scout for the Grand Ole Opry would be in attendance. After the band loses a member, Cash, Copper is recruited to perform after the band hears him sing. Impressed, they offer him a position, which Copper accepts after promising he is a stray. However, his friendship with the band causes him to forget a promise to watch fireworks with Tod.

Tod would later reveal to one of the band members, Dixie, that Copper was not a stray. The two formed a plan to get Copper to leave by leading Amos Slade to the fair. However, the resulting chase ruins the band's performance, resulting in the talent scout leaving, leading to Copper's removal from the band.

Copper and Tod would later admit their mistakes and work to reunite the band. Copper uses his tracking skills to find the talent scout, and he and Copper work to trick the band, including Cash, into coming. Copper helps the band work out their differences, leading to the band performing their song. The talent scout notices the group and is impressed, so he arranges to let them perform at the Opry. However, Copper chooses to leave the band to return home with Tod.

House of Mouse
Copper and Tod appear briefly in the episode "Dining Goofy", running out of the club with other Disney dogs and cats when Goofy spreads a rumor about the club being infested with fleas.

Trivia

 * In Spain and Italy, he is named "Toby".
 * Some of Copper's growls when he fights the bear and tries to attack Tod and Vixey in their burrow are recycled from Old Yeller when Old Yeller was fighting the wolf.
 * Copper's revenge on Tod is somewhat similar to Zira's revenge on Kovu. Both stay angry and explain about their family relationship's avenging (in Copper's case, Chief falling off the train track and in Zira's case, Nuka getting crushed by a log), but Copper is a hero while Zira is a villain and Chief was Copper's foster father as Nuka is Zira's son.
 * Copper is one of many bloodhounds in Disney films, with the others being Bruno, Trusty, Towser, and Napoleon.