Humphrey Bogart was affectionately known as the “Bogie” of show business in Hollywood. Given that he was in the Navy during WWI, the nickname suited him well. When he was deployed to the military police, he was struck in the mouth by a prisoner. The injury did not kill him, but left a scar on his mouth that caused him to lisp whenever he spoke.
His characteristic injury, combined with his raspy voice, made him the perfect person to take on any tough-guy gangster role that he was known for during his second career. It’s interesting because he appeared to be the ultimate evil person, but he also suffered from severe stage fright.