Signer Dragon

The Five Dragons are a series of cards, introduced in Yu-Gi-Oh! 5D's. They play a part in the legend of the Crimson Dragon and the Signers. Each of the five Signers possesses one of the Five Dragons.

Currently, four of the five are known, all of which are Synchro Monsters:

Stardust Dragon (Yusei Fudo)

Red Dragon Archfiend (Jack Atlas)

Black Rose Dragon (Akiza)

Ancient Fairy Dragon (Luna)

Buster Monsters
Along with the Five Dragons there are a series of monsters known as "Buster Monsters". They are seem to be powerfull versions of the Five Dragons. They can only be special summoned by the effect of the "Buster Mode" trap card. Currently the only "Buster Monsters" known are:

Red Dragon Archfiend/Buster (To be realesed in Crimson Crisis booster pack)

Stardust Dragon/Buster (This card will be realesed in the OCG with the Duelist Box)

Summoning Quotes
In the Japanese anime, when Synchro Summoned, their corresponding Signers chant a quote that describes them.

Yusei Fudo
"Clustering hopes become a new shining star! Become the path its light shines upon! Synchro Summon! Take flight! Stardust Dragon!"

Jack Atlas
"The ruler's heartbeats will now file through here! Take witness to its creation-shaking power! Synchro Summon! My very soul! Red Demons Dragon!"

Akiza
"Chilling flames engulf the entire world! Pitch-dark flower, set into bloom! Synchro Summon! Appear now! Black Rose Dragon!"