High Roller is a human warlord reigning at East Citadel. Because of his hatred of humans, he convinced the animal kingdoms to betray them and thus plunged Hidden Kingdom into war. This in turn led to the creation of Big Green, which became his sworn enemy. He was also a henchman of Twin Masters.
In his youthful days, High Roller was a generally harmless, if impishly malicious, child. He was at that time a classmate of both Woo the Wise and Infinitum, the former of whom becoming his rival due to their disparate ideologies regarding their studies; namely, Woo believing in the great importance of education and High Roller professing the superiority of more pleasurable things, such as comic books. It was during this time that High Roller began to hone his charismatic skills by persuading his classmates with objects such as candy.
At an unclear point in his life, HighRoller trained under Chiung Ming. It is unknown under what circumstances this occurred, as Chiung Ming was imprisoned what was implied to be a long time ago.
Later in life, High Roller would become a happy court jester, laughing and playing games. But, in a typically arrogant move, he insulted the former Emperor of Hidden Kingdom and was immediately cast from the great East Citadel. He wandered alone in the forest, brooding and learning to hate humans. As fate would have it, he was struck by lightning, and gained the ability to speak the language of animals. He quickly discovered animals' great weakness for candy and bribed them with sweets. Many animals joined his cause and helped kick humans out of their homes and castles. Now many animal kings and queens pay homage to High Roller and do his bidding.
As the emperor of the East Citadel, High Roller generally makes a point to do whatever he wants and what he typically wants to do is attack humans, or more accurately, get animals to attack humans for him, eat candy and play games. In fact, High Roller is a master of many folk games and these skills actually translate to the battlefield in dangerously unexpected ways. Combine this with the fact that he likes to play dirty, and High Roller is a formidable opponent for even the most skilled members of First Squad!
At unknown points in his life, High Roller met both Chiung Ming and Twin Masters, and even served Twin Masters for a while. During the final battle with Twin Masters, High Roller refused to work with Big Green to form the Bronze Giant. He was last seen leaving his brief ceasefire with Big Green, accompanied by his zebras and Bearstomp.
High Roller is very selfish and usually acts like a spoiled brat kid. He is quick to anger, and will often become livid with rage when things do not turn out his way, usually throwing tantrums when this happens. He also becomes bored just as quickly, and often needs to find various activities to entertain himself. He only puts the strongest animals in his army to guard him, such as the eagles. Despite his childish and selfish desires, he does have a little honor, such as the time he stopped the Zebra Brothers from destroying the Bell Tower. However, he then destroyed it himself in a fit of rage. Likewise, he has been known to honor agreements and bets, even when he held the military strength to go back on his word, such as when he freed Big Green's troops when Lin Chung won his bet and showed him something more impressive than Chameleon Queen's giant screen.
High Roller also very often acts like a bully, to try and get his own way, as seen in many instances, notably when he pinches Chameleon Queen and makes her cry, making her do as he wants.
While he gains more and more skill, High Roller refuses to accept the fact he is a human, the very species he grew to hate due to throwing him out.
High Roller is quite short, and wears a blue emperor robe that has long sleeves that usually cover his hands, and has a yellow Chinese lollipop symbol on the front of it. He also wears a black hat with an arrow sticking out, black shorts and red shoes with white soles. His right eye appears to be blind, with a grey iris ring and no pupil, while his left eye has a black pupil and a black cog wheel-like pattern around it. He has a small red nose, a shaven scalp, pointy teeth, and pale skin.
In folk game competitions, HighRoller wears a red skintight suit with a gold dragon on the front.
Judging by its pale colouration and lack of pupil, High Roller's right eye may be blind, though this is not confirmed. In "Folk Game Competition II", in the flashback dream at the start, High Roller's right eye was not like this, yet at the current time, it is. It is currently unknown why this is, as High Roller has never mentioned anything about his eye at all.
Also, if indeed his right eye is blind, it does not appears to affect High Roller in any way.
In the Chinese dub, High Roller was Kao Chao; in the Chinese version, he was the true emperor until a magic arrow shot his head stealing his ability to speak English but gaining the ability to speak animal language instead. In the Romanian dub, he was renamed Sportiflex.
As seen in earlier drafts, High Roller's arrow originally went through his head, the ends poking out his ears. This is likely a reference to him being shot by the arrow in the Chinese dub.