Twitch - The Plague Rat

Twitch

The city-state of Zaun is a twisted realm of science and magic ran amok. The air is choked with pollution from the countless factories and magic labs that spew waste into the sky. As polluted as the sky is in Zaun, its subterranean levels are far worse. The waste products of Zaun's many different scientific and magical endeavors have flowed together in its sewers, mixing into a toxic and mysterious concoction. Rising up from this alchemical nightmare is a single plague rat. Unlike his un-evolved cousins, Twitch (as he calls himself) can talk and read and interact with the world as well as any of the other sentient being in Valoran. Twitch has come to the League of Legends to represent himself—the only one of his kind—on the Fields of Justice.
While Twitch's true motivations remain known only to him, his prowess in the arena is a matter of public record. As a creature of the sewers, he is able to blend in with the shadows and ambush an unwary victim of his choosing. He has collected a significant quantity of the toxic soup that collects in Zaun's underground, which he coats his crossbow with. The effect of being shot with one of Twitch's crossbow bolts is extremely debilitating. Even without his poison, he will outright infect those he chooses to attack courtesy of him being a plague rat. As an act of desperation, Twitch may rapidly unleash a flurry of bolts at his foes. He madly peppers the area he focuses on, though the damage is reduced.

Tristana - The Megling Gunner

Tristana

The Megling Commandos are something of a legend in Bandle City. They have a history that spans centuries, and they remain the oldest yordle military unit still in service. They are renowned for their courage and bravery, as well as their deadliness and ruthlessness, making them the most respected and feared of all warriors in Bandle City. Legends of Megling, the valiant founder of the commandos, can still be heard whispered throughout Valoran and it was these legends that most fascinated young Tristana. Since she was a wee child, Tristana wanted nothing more than to become the crack shot that her idol was all those years ago. She trained her entire life until she was old enough to join the military and could attempt to earn the rank of Megling Commando. The senior officers were impressed by her abilities, claiming that Tristana was a natural, and she realized her dream that day as she donned her Megling fatigues. Though her heart lies with her unit, the call to the Institute of War was greater still and now Tristana honors her tradition and protects her people as a champion in the League of Legends.

Found at: http://lol.qq.com/main.shtml

Teemo - The Swift Scout

Teemo

As far as yordles are concerned, there is something slightly wrong with Teemo. While he enjoys - and in fact needs - the level of community and companionship inherent to all yordles, Teemo feels it so strongly that he ventures out on his own to destroy the enemies of Bandle City. There is something that switches off in Teemo, so that the lives he ends do not burden him. It seemed only logical to send him to fight in the League of Legends as the champion of Bandle City. He has taken to the League like a duck to water, seeking out the foes of the yordles and extinguishing them with the rare ajunta poison he personally gathers from the jungles of Kumungu. However, the limited company of his own kind wears on Teemo, and cracks are beginning to show in his innocent and chipper facade.
Teemo is a small champion that moves fast and strikes true. As a scout, he blazes trails to his enemies that make it easier for his allies to follow. He can, despite his small size, move at blinding speed, using the terrain to his advantage. His mastery of ajunta poison also gives him a distinctly potent weapon. Prepared one way, his wicked little darts cause blindness in his foes; prepared another, they cause a slow, lingering death. Teemo also prepares traps for those tracking him, which unleashes a poison that slows and harms enemies.

Taric - The Gem Knight

Taric

There is an ancient form of magic, forgotten by many and discarded by some. It is the magic of the earth, of the resonance of crystals and gems. Taric's father was a healer in their city, on a world far away. Taric was always interested in his father's pursuits, even from a young age. Despite his burgeoning understanding of herbs, plants, and animal medicines, it was the power of gems that most fascinated the growing boy. It wasn't long before Taric had exhausted his father's coveted library and set out on a path of his own. He wasn't to be a healer, but a defender - one who used the power of the earth to preserve and protect. Quickly, Taric became a wandering knight, renowned across the land. That is, until the day a spell of summoning grabbed him from his home and deposited him on Runeterra. Now, Taric misses his world, though he is happy to fight in the League, protecting all who are in need.

Found at http://lol.qq.com/main.shtml

Urf - The Manatee

Urf

.Despite the traditionally peaceful ways of his people, Urf the Manatee idolized the strength and prowess of Champions in the League of Legends and strived to become one. Of all the League's Champions, there was none that Urf admired more than Jax The Armsmaster. Since the introduction of the arena, no man has forced the League of Legends to revise their regulations more often than Jax, and the self-proclaimed Grandmaster at Arms rattled off a streak of consecutive wins 152 long. In order to compensate for the extreme power of this Champion, the League created special sanctions for Jax: He is only allowed to fight with weapons the League deems suitable. For now, that list includes a lamppost, a chicken's foot, a spatula, and a fishing rod.
In his admiration and pursuit to become a weapons master like Jax, Urf has equipped himself with the two great symbols of his Manatee heritage as his weapons: a fish (to symbolize the bounty and providence of the sea) and spatula (to pay homage to his people's age-long pursuit for culinary mastery). Urf now begins his aquatic journey as the League's first Manatee Champion, hoping one day he will have the opportunity to cross fish and spatula with chicken's foot and lamppost.