Deadmen

Deadmen (デッドマン, Deddoman) are people who are infected with the Nameless Worm which enables them to do extraordinary things with their blood. Most of them were infected during the Great Tokyo Earthquake.

Ganta Igarashi is an exeption for he was infected much later by a unique Nameless Worm by the Wreched Egg herself, during the Nagano school massacre. He became a Deadman with a unique ability, that is the key to the Mother Goose System.

During the Great Tokyo Earthquake, pieces of a certain Red Diamond were found. The Deadmen yet to come somehow inhaled or swallowed a piece of the Diamond. The Red Diamond is a capsule for the Nameless Worm and so the Nameless Worm settled in the bodies of the Deadmen and gave them the Branches of Sin. Those Nameless Worms were somehow created or released by the Wretched Egg.

Capture
The privately owned prison, Deadman Wonderland, is a facility where Deadmen are held (more specifically the G Ward). They are used to compete against each other in the Carnival Corpse. Tamaki did research on the Nameless Worm and was able to create artificial Deadman: the Forgeries from data he thought he obtained form the "old man's" computer. The Forgeries powers based on a supposive Anti-Wreched Egg posion this however turned out to false as the real data was hidden.

After the secret of the Deadmen were revealed, many of them were released to the outside world on probation. Though many could not adjust to normal life.