Buck (Planet of the Apes)

"Thank you."

- Buck's final words before his death. Buck was an extremely powerful gorilla and an ally of Caesar. He was the only ape who was never harassed by Dodge Landon. He was bad tempered, strong and brave, and was seen trying to get out of his cage. He was freed by Caesar but refused to go out, after a few seconds Buck quickly dashed through the play area and began playing with the toys the other apes played with.

Rise of the Planet of the Apes
Buck was first seen by Caesar trying to escape the cage, after noticing him, Caesar decides to let him out so he can respect him.

Death
After all the apes defeated the humans, Jacob's helicopter started to shot Caesar but Buck sacrificed himself by going at the helicopter and getting shot multiple times causing him to enter the helicopter that explodes causing him to die.