Sergeant Graves is the codename of one of the founding members of the Knights.

Sgt. Graves real identity is unknown. He claims to be a soldier who was killed in a poison gas attack in the trenches during World War I. Captain Redeagle validated this claim, because he knew the soldier, who was in fact a Sergeant, before he was killed and they served together in World War I. Captain Redeagle was a biplane pilot and often fought in the same battles, and knew the location of the sergeant's unit when it was exterminated. Furthermore, he says he landed after the battle and went in to the trenches to retrieve his body. However, he discovered his friend had died in a muddy stew of heinous chemicals within an ancient Celtic burial mound the soldiers had accidentally cut through with their trench. Captain Redeagle says he witnessed his friend return from the dead.

When he rose from the muck, it was not a pleasant resurrection. Sgt. Graves was not only horribly burned and scarred from the artillery shelling and poison gasses, he was deathly gray. He was deeply saddened by this development. However, he was a realist, thus accepting this new reality as a reanimated corpse from the grave, the soldier adopted the name Sgt. Graves and began seeking vengeance against those who wage war. Out of respect for his friend's wish to let his human self remain dead, Captain Redeagle never revealed Sgt. graves' true identity.

Sgt. Graves served out World War I with distinction, much to the horror of his commanders, and has since seen action in hundreds of wars worldwide for a full century. Though he has a particular hatred of Germans, he universally despises violence and war and will stop at nothing to kill all who wage it in the most violent way possible. Over the last hundred years he has become a master of every weapon and form of combat known. He has also proven impossible to kill.

The only break he has taken from waging war on warriors, was during his years serving on the Knights. Convinced to join by his old friend Captain Redeagle, Sgt. Graves helped found the team in 1940. But with Captain Readeagle's death in 1945, Sgt. Graves decided to quit the team and go back to waging war against war.

He was very active in Kandahar Province in Afghanistan during the 2000s and was last seen in Syria last year. Sgt. Graves has not been seen in recent months.