The Wild Dragon.

Rhaegar Targaryen is the only son of Aemma and Viserys Targaryen, Heir to the Iron Throne, but many don't wish him to lead even his father has his doubts.

Rhaegar is wild and mostly doesn't think about his actions. Therefore, many believe he will bring more harm to the realms than good. He's 16, and his father still hasn't named him Prince of Dragon Stone.

Rhaegar has claimed one of the biggest dragons to live right now, son of Meraxes and Balerion, and almost 120 years old. Diaval was never claimed. Some tried, and they all died. All until a little 7 year old boy walked into his den and came out laughing, sitting on top of the large dragon.