There are 4 main Chaos Gods:
Khorne, also known as The Blood God, Skull Lord, and Master of Battle, is the Chaos god of murder, rage and war. Khorne is the most powerful and eldest of all the Chaos godes. He despises magic, showing dislike for Tzeentch. His opposite and most hated enemy is Slaanesh. The chaos god Khorne is thought to sit on a mountainous pile of skulls, rising above an ocean of blood. His daemons reflect his nature; they are all vicious and deadly close combat fighters, often battling amongst themselves if not presented with new targets.
Nurgle, also known as The Plague Father, Father Nurgle, and The Great Unclean One, thrives off death,decay, and disease. Nurgle lays waste to his enemies by tormenting them with his lethal and agonizingly painful plauges and toxins. His daemons manifest as creartures straight from nightmares, bloated, rotting, and disease ridden monsters, they advance slowly and steadily, unleashing the most horrific plauges the universe has to offer on all that stand before them.
Tzeentch, also known as The Great Changer, The Lord of Change, is the god of evolution, change, hope, and lies. Tzeentch, his daemons and mortal champions are all leathally potent sorcerors and psykers, lauching storms of burning, mutating magic at their opponents. His lesser daemons appear as maddening creatures, constantly shifting and morphing their appearences. His greater daemons, known as Lords of Change, appear as bird-like humanoids, with huge, shimmering wings that constantly shift color.
Slaanesh, also known as the Dark Prince, The Prince of Excess, and to the Eldar, She who thirsts, or The Great Destroyer, is the god of pleasure, pain, and excess. Created accidently by the decadent Eldar civilization more than 10,000 years ago, Slaanesh is the (relatively) youngest Chaos God in existence. Slaanesh manifests as a tall, beautiful humanoid, with long locks of blonde hair and a mixture of a man and woman. His daemons tend to follow this trend, alos appearing as hermaphrodotic. His lesser daemons, known as Daemonettes, appear as disturbingly beautiful creatures, giving off pleasent and intoxicating musks.
Forces of Chaos
Lost and the Damned
Lost and the Damned is a name given to the broad spectrum of renegades and criminals that follow Chaos. They range from military deserters to the most denegerate of beings, barely recongizable as once human. The majority of any Lost and the Damned army is made up of hideous Mutants, residents of the cursed Daemon Worlds and toxic wastes. Alongside them are Traitors, men and women who choose to reject the Emepror's light and flock to the traitor warbands in hopes of fame, wealth, and power. They come in many types, such as former guardsmen to mercenaries, bearing a wide variety of unifroms and weapons. When used by powerful chaos champions, like Chaos Space Marines, they are lttle more than cannon fodder, attacking in seemingly endless hordes, exhausting their enemies morale and ammunition.