New York - Viacom's Nickelodeon children's network said on Tuesday it will launch several online features to complement its animated TV series, "Avatar: The Last Airbender." An animated online comic book from the series' creators, online game event, and new Avatar shorts will be added to a dedicated site. Kids can watch the show on Saturdays and use cheats announced on-air to unlock online animated shorts, as well as new levels in an online game.