Griffin became severely mentally handicapped after he consumed the drug called "banana fish".
Griffin has a very depressed face and long brown hair from the front. His face is somewhat similar to Ash's, but he is older and more vacant. He shares Ash's eyes.
Griffin served in the American military, he came to be posted in Vietnam/Iraq during the Vietnam/Iraq war.
Griffin has a close relationship with his brother. They were close growing up and Griffin often looked after Ash.
They were close to the extent that after he was shot and became mentally handicapped after the war Ash took him in and did everything to try and make him better, using all of his illegally earned money to try and get treatment and medicines for Griffin.
When Griffin is killed by Abraham, Ash becomes enraged and does his best to avenge his brother.