As a silverback grows up it grows a gray sort of hair on its back and their chests grow larger. The silverback can stretch tall and stare into the the eye's of an other animal to scare it away. The animals gorillas fear are leopards and humans.
Full grown males may stand 6 feet (1.8) tall. They weigh up to 400 pounds (181 kg). Females weigh up to 200 pounds (91 kg) and are half as tall as males. They have a jutting jaw that has 32 teeth like humans and other apes.
When gorillas walk they lean over and put there weight on the back of there knuckles. This is called knuckle walking,only gorillas and chimpanzees move this way.