Joker is the Circus Master as well as the Chief Prison Guard of Wonderland's Prison Realm. He is not liked by the other roleholders, but is respected by Alice. He has two different personalities which are known as black and white. The Jokers have a mask in which they can communicate with each other from different areas. Black Joker is the foulmouthed and condesending side while the White Joker is the polite and modest side to Joker.
Joker no Kuni no Alice (Game)
Joker is the holder of the Circus in which, according to the rules, all of the roleholders must come to the shows. Alice keeps getting lost and always finds Joker. Depending on the route you play in, The character you pick Alice to love will come to her rescue before they can hurt her. Both Jokers get shot in the most brutal ways possible, but can't die unless Alice kills them herself. Black Joker is seen killing Alice's sister Lorina Liddell.