Amumu - The Sad Mummy

Amumu

Perhaps one of the oddest champions in the League of Legends is the yordle known as Amumu. His life before joining the League remains unknown to all - especially Amumu. All he remembers is that he woke up alone inside a pyramid within the Shurima Desert. He was wrapped in mummy wrappings and he could not feel his heart beat. Furthermore, he felt a deep sadness that he could not entirely explain; he knew he was missing his parents, though he could not remember who they were. Dropping to his knees, Amumu wept into his bandages. No matter what he did, it seemed he could just never stop his tears or sadness. Eventually he got up off his knees to mope and wander the world, making his way to the League; it would seem that even the raw power of unleashed emotions can be used to benefit the plans of summoners.
To this day, Amumu remains a very sad mummy, occasionally experiencing moments of extreme anger followed by bouts of crushing depression. It is during these times that it is best to stay out of his way, or you may find yourself wrapped up and strangling inside his tear-stained bandages.

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

Amumu Pumpkin Carving - Found on the LoL Forums

Alistar - The Minotaur

Alistar

The mightiest warrior ever to emerge from the minotaur tribes of the Great Barrier, Alistar defended his tribe from all of Valoran's many dangers; that is, until the coming of the Noxian army. Alistar was lured from his village by the machinations of Keiran Darkwill, Baron Darkwill's youngest son, and commander of the Noxian expeditionary force. When Alistar returned home, he found his village burning and his family slain. Bellowing with rage, he charged an entire regiment of Noxus's elite, slaughtering them by the hundreds. Only the intervention of some of Noxus's most skilled summoners checked Alistar's rage. Brought in chains to Noxus, Alistar spent the intervening years as a gladiator pitted in endless battle for the entertainment of Noxus's wealthy leaders. Alistar's once noble soul slowly twisted, and he would have been lost to insanity if not for Ayelia, a young servant girl who befriended him and eventually arranged for his escape. Suddenly free, Alistar joined the newly-formed Institute of War as a champion, hoping to one day visit his final vengeance against Noxus and to find the girl who once again gave him hope.

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

Here is a video showing Alistar's Joke, Taunt, Laugh and Dance Sequence

Akali - The Fist of Shadow

Akali

There exists an ancient order originating in the Ionian Isles dedicated to the preservation of balance. Order, chaos, light, darkness - all things must exist in perfect harmony for such is the way of the universe. This order is known as the Kinkou and it employs a triumvirate of shadow warriors to uphold its causes in the world. Akali is one of these shadow warriors, entrusted with the sacred duty of Pruning the Tree - eliminating those who threaten the equilibrium of Valoran.
A prodigal martial artist, Akali began training with her mother as soon as she could make a fist. Her mother's discipline was relentless and unforgiving, but predicated on the fundamental principle: "We do that which must be done." When the Kinkou inducted her into the order at the age of fourteen, she could slice a dangling chain with a chop of her hand. There was no question – she would succeed her mother as the Fist of Shadow. She has had to do much in this role which others might find morally questionable, but to her it is in service of her mother's inviolable doctrine. She now works with her fellows Shen and Kennen to enforce the balance of Valoran. This hallowed pursuit has unsurprisingly led the triumvirate to the Fields of Justice.

Here is a video showing Akali's Joke, Taunt, Laugh and Dance Sequence

Here is Akali's Champion Spotlight where Riot Employee Phreak demonstrates his capabilities.