Mark of the Dragon

A Mark of the Dragon, known as a Dragon Birthmark in the Japanese anime, is a special mark that indicates that a person is a Signer.

5,000 years ago, an ancient civilization known as the People of the Stars worshiped a mystical light called the Dragon Star, which was prayed on by the leader of the People of the Stars, the Star Dragon King, at the top of the Sanctuary of the Sky.

When the star shined, the King knew it would be a message from their god, the Crimson Dragon. The dragon was then summoned to imprison an incarnation of an ancient evil in the earth. This evil is represented in the Nazca Lines.

According to legend, the Crimson Dragon could only by summoned with the help of the Signers, whose individual marks either represented the Left Claw, Tail, Wings, Right Claw, and Head of the dragon. These people are being searched for by a group known as Yliaster, led by Rex Goodwin, and disguised as the Public Security Maintenance Bureau. According to what Rex Goodwin told Yusei, he organized the Fortune Cup not only to confirm the identities of Yusei, Jack, Akiza and Luna as Signers, but also in order to awaken their powers so that they could fight against their nemesis, the Dark Signers.

These Dragon birthmarks belong to:

Previous owners of a Birthmark:

Rudger´s severed arm, which was severed once the power of the Dark Signers overcame the power of the Signers, and bearing the Head birthmark is currently in Rex Goodwin´s possession. Unlike the other birthmarks the head appears on the left arm, whereas with the other four appear on the Signers' right arms. In the English anime, Rex Goodwin claims to be the fifth Signer, but in Episode 64, Crow becomes the fifth signer by obtaining the Dragon Tail Birthmark.

While the Dragon Head Birthmark appeared on the Signer left arm previously, it appears on Yusei's right arm.

In the English dub, after seeing Yanagi's sketch of the Crimson Dragon, Yusei assumes that his mark is the Dragon's Head. A similar thing happened in the dub when Rex spoke to Jack at the Stairway to the Dragon Star before the Fortune Cup. Instead of possessing the wings birthmark, as he did in the original, Rex tells Jack that he possess the left wing. It is not known if these were mistakes, or if they are changes made by 4Kids in the dub's plot.

The mark also indicates a deep connection between each Signer. This being represented on numerous ocassions, furthermore before they're about to Duel against a Dark Signer. Whether one of the Signers is about to fight against one of their nemesis in a Shadow Duel. The others become aware of this as their corresponding Mark of the Dragon reacts by glowing and throbing.

The Mark of the Dragon rivals the Dark Signer's dark mark. Whenever a Signers is in the presence of one of the Dark Signer, both of their marks react. In this case, the Signer's birthmark more painfully sears into their arm.

Towards the end of Yusei's rematch against Kalin some strange event ocurred to all of the birthmarks. When Yusei desperately tried to help Kalin avoid crashing on his Duel Runner, the marks vanished from their owners' arms and combined into the image of the Crimson Dragon, which appeared on Yusei's back. After that, he was ready to summon a Savior monster because he desperately wants to save someone even though he is evil. The same goes to Jack when he wants to save Carly. Rex Goodwin did something similar to this in his 3-on-1 duel against Yusei, Jack, and Crow where he consciously called all five marks together to form the Crimson Dragon Mark on his chest

Non-canon
In Yu-Gi-Oh! 5D's Stardust Accelerator, the player's character has a Mark of the Dragon on their arm. This mark was artificially placed on him/her by Rex Goodwin in an attempt to use technology to awaken the Crimson Dragon.