Bed of Chaos is kind of similar to the Dragon God boss in Demon's Souls, in that you have to do a few scripted things before you're able to go after the boss. It's a very easy boss once you know what to do and it's the only boss in the game where if you die, your progress is saved. When you go through the fog gate and slide down the huge ramp, you will notice two orange bubbles on either side of the main boss; this is where you will want to go. The boss only really does a sweeping motion with its arms, so as long as you have a good shield and keep it up while running to them. When you reach the first orange bubble (doesn't matter which one you go to), either roll through or attack the branches and then attack the glowing yellow spot. This will trigger a cutscene where the boss grows a scythe-like appendage from its back. It will use this to try and stab you, so keep moving. As you go towards the next orange bubble, you will notice that pieces of the floor will crumble; be careful not to fall or get pushed into the holes. You can be safer if you stick to the non-tiled, circular portion of the floor. Once you destroy the second glowing root in the second orange bubble, all hell will break loose. It grows another appendage and now little pillars of fire will spew forth from the floor; you can tell where they are since you will see an orange spot on the ground before it comes up. You have to make your way to the center, where you will find a hole has opened up and there is a large root that acts as a path to the center. Jump onto this root and break through the branches to get to the "heart" of the boss, but be careful as the flame pillars can reach you in here; one hit to the "heart" will kill the boss.