Grand Theft Auto IV: The Lost and Damned features a number of new characters, including a new main character, Johnny Klebitz. The new characters are mostly members of rival motorcycle gangs, known as "The Lost Brotherhood" and "Angels of Death."

Voiced by Scott Hill, Johnny Klebitz is the main character in Grand Theft Auto IV: The Lost and Damned and is the character the gamer will play as during the main single-player game. At the beginning of The Lost and Damned, Johnny is the acting vice president of the Liberty City motocycle game known as "The Lost Brotherhood." He's filling in for the gang's president, Billy Grey who is in prison. Throughout his time leading the gang, Johnny has been able to keep a relative peace with the gang's rival, the "Angels of Death."

Johnny was referenced in the main story of Grand Theft Auto IV and was introduced to Niko Bellic by Elizabeta Torres. Elizabeta wanted Niko and Playboy X to accompany Johnny on a heroin deal, which eventually ended in a shoot-out with the Liberty City police.

Later in Grand Theft Auto IV Johnny was asked to accompany Niko on a diamond deal with the Jewish Mob, but Klebitz betrays Niko during that deal when they're ambushed and makes off with the money.GTA Wiki: Johnny Klebitz

Billy Grey is the leader of "The Lost Brotherhood" and is incarcerated at the beginning of The Lost and Damned. Billy is thought to be the reason behind most of the violence between "The Lost Brotherhood" and their rivals. Trailers and gameplay clips from The Lost and Damned suggest one of the main plot points of the game will be friction between Billy and Johnny once Billy is released from prison.GTA Wiki: Billy GreyGameTrailers: GTA IV: Lost and Damned Story Gameplay

Jim Fitzgerald is a senior member of "The Lost Brotherhood" and is known as the right-hand man of Johnny Klebitz. Jim is said to be in agreement with Johnny on his stance against the violence between "The Lost Brotherhood" and their rivals.

Jim is seen briefly in the main story of Grand Theft Auto IV when his is killed by Niko Bellic on orders from Ray Boccino.GTA Wiki: Jim Fitzgerald