Monkey D Dragon

 
Dragon as he appeared 24 years ago, during Roger's execution.

Monkey D. Dragon

Monkey D. Dragon is the father of Monkey D. Luffy and the son of Monkey D. Garp. He is the infamous Revolutionary leader who has been attempting to overthrow the World Government. He is the World Government's greatest enemy and is the most dangerous and most wanted man in the world.

Dragon is usually seen dressed in a long green cloak (colored black in the manga), underneath which he wears the garb of a revolutionary, colored white in the anime, and orange in the manga. He has spiky black hair with a widow's peak hairstyle, and what resemble tribal tattoos on the left side of his face (which he received sometime after Gol D. Roger's death), they are colored dark red in the anime, and bright red in the manga. Also, he appears to have no eyebrows, however, he does have a bit of stubble on his chin in the form of a goatee. He is most often seen sporting a sinister grin on his face, further aiding his already intimidating visage. Only on rare occasions, such as at Roger's execution, has Dragon not been seen smiling.
24 years ago at Roger's execution, his appearence was the same as it is now except he did not have his tribal tattoos or his goatee.

Dragon's personality is mostly unknown due to the many mysteries surrounding him, save for an apparent love for freedom and a belief in fate, traits of a "D".
But unlike other members of his family, or D's for that matter, he has a stern and serious demeanor, however in all of his appearances thus far, except at Roger's execution, he is seen with a smug grin on his face. However, years prior to the main story he was seen rather shocked when hearing the reason of Sabo's plea for help and rejection of his own Noble heritage.
He also seems to care about innocent people, as shown where he willingly saved the people of the Gray Terminal and allowed them to join the Revolutionary Army.

He speaks as though he is a mystic of sorts and apparently doesn't like to speak of, or be asked about, his past. He also has a strange habit of always looking towards the East Blue when the wind changes. His revolutionary comrade Emporio Ivankov attributes this to his instincts, having left Luffy in East Blue.

 Dragon's history remains mostly a mystery, aside from him being born in the Goa Kingdom. Thus, it is unclear why Luffy was left to be brought up by his grandfather Garp instead of Dragon himself. At some point, he began the Revolutionary movement becoming its leader and his ideals began to slowly spread throughout the world. One by one, countries slowly began to support him, though sometimes through war. He was shown to have witnessed Gold Roger's execution, but he had not yet acquired his tattoo at this point.
Twelve years before the current storyline, Dragon returned to his home in the Goa Kingdom and witnessed the burning of the Gray Terminal. After witnessing the sorrow of its own people by way of Sabo, with the boy begging for help and claiming shame of his heritage, Dragon enacted a plan in order to save the people and embarrass the government by creating a causeway to allow for those on Trash Mountain to escape and join him. Due to his actions, the nobles merely noticed that the charred remains from their burning of the mountain was far less than anticipated.
Sometime later, the Revolutionary Army docked in Shimotsuki Village for food and supplies, coincidentally close to where Roronoa Zoro was currently training. There, Dragon is seen on his ship, being scolded by Ivankov for being late. This is also apparently where he obtained the distinctive tribal-style marks that run down the left side of his face, which may very well be a tattoo.^[9] In the anime, Ivankov asks Dragon where he's been, to which he replied that he'd been at the World Noble reception ceremony on Dawn Island. When Ivankov indignantly asks why he wasn't invited, Dragon told him that he attracted too much attention, probably because of his enormous head. ^[10] Then Dragon asks if they have enough food. When he hears that the local dojo had resupplied them, he nods before announcing that they were returning to Baltigo.

Thalassa Lucas holding up a photo of Dragon 8 years ago.

Eight years before the main storyline, the Council of Kings gathered at Mariejois to discuss Dragon's revolutionary movement and his ideals, both of which were threatening the World Government.
Thalassa Lucas showed his picture. It was then he revealed that Dragon was currently no real threat, but would become so in five to six years or so, if not dealt with.