Red was an altered gorilla and the secondary antagonist turned anti-hero of War for the Planet of the Apes. Red was one of Koba's followers who defected to Colonel McCullough's forces and has the word "DONKEY" tattooed on his back.
Red ultimately had a change of heart after seeing the destruction he had been supporting of his own kind, Caesar's words eventually convincing Red that he would always be viewed as inferior by the human soldiers so much so that he gave his life so Caesar could destroy the soldier's compound.
War for the Planet of the Apes: Revelations
Red was shown early in the story to be questioning Caesar's leadership, disliking the fact that Caesar had let the humans go after killing Koba. He went on to convince Grey to leave Caesar's army to create a colony of their own, along with others that were loyal to Koba. Grey became their leader, though it was Red behind their schemes.
Red lured the humans to the building in which Caesar had hidden the females and young, knowing that the attack would prompt Caesar to send the females and their children back to the safety of the forest. Some of the Gorilla Guard accompanied them to keep them safe, Red included. However, Grey and the others in their secret group slipped away to follow them without Caesar's knowledge.
With the help of their group, Red and Grey managed to subdue the females and the Gorilla Guard, convincing them that Caesar and the ape army had all perished and that Grey was the new king. Cornelia had escaped, however, and they sent some of their loyal apes to find her with orders to kill her, so that the rest of the females, leaderless, would succumb to Grey's leadership.
When push came to shove, however, Grey stood against Red in his bid to kill Cornelia during the birth of one of the females. He stated that it was against custom and that they would wait until after the birth to seize the former queen. This enraged Red, who attacked Grey, and the two of them brawled until Red got hold of a gun and shot Grey point blank in the face, killing him. The gorilla was then descended upon by the females, and retreated in humiliation to have lost to their mob.
War for the Planet of the Apes
Red was present with the group of soldiers who attacked one of Caesar's outposts in the forest, the gorilla providing ammunition and grenades for the soldiers to use. He was later captured, branded a traitor by the apes. However, he spoke out against Caesar's claims he feared him, prompting one ape to strike him to the ground. The gorilla Winter then forced him outside. However, Red managed to overpower the gorilla, threatening to kill him if he didn't reveal where Caesar's main base was, Winter giving in. Red then returned to the humans, informing them of Caesar's location. As promised, he allowed Winter entry into to be one of the Colonel's "donkeys".
Red was later watched by Caesar, Luca and Maurice helping the soldiers pack their gear. A few days later, he encountered Caesar's co, only with the soldiers, helping them capture nearly all the apes and helped string the near dead ones on crosses to be made an example of. He found Caesar near one cross trying to help his dying ape, proceeding to knock him out with the butt of his rifle.
Unfortunately, he was later shot in the head because he betrayed the humans to save Caesar's life.