Hellkite Dragon

Souls

 * 10,000 (First playthrough)
 * 50,000 (New Game Plus)

Obtaining the Drake Sword
The Drake Sword is obtained by doing enough damage to the drake. Unlike other monsters the tail does not need to be cut off. An easy way to obtain the sword is to purchase ~100 arrows and the short bow from the Undead Merchant in Undead Burg and fire up at the drake from the lower part of its bridge.

Ranged Option
In order for you to get the infamous Drake Sword with arrows only, make sure to have at LEAST a dexterity of 15 and a bundle (get at least 75 to take into account all the shots you'll miss) of Large Arrows. If you do this right and have a bit of patience you can simply shoot the dragon on the far end of the bridge 15-20 times for the tail to fall off after it moves to the bridge from your last attack. Also note shooting the tail is a great way to anger the Drake and set fire to the enemies above you every time you pass through for a quick 300 souls at the cost of a single arrow.

Alternatively, you don't have to shoot the tail to get the sword. As long as you hit the dragon anywhere with approximately 50 arrows the tail will fall off and you will be rewarded with the Drake Sword. Walk into the room with the three Undead Rats and kill them. Now walk back out of the room and go right. Walk as far to the right as possible. From this spot you should be able to hit the dragon in the head. Shoot him in the head once and wait for him to drop onto the bridge. When he's on the bridge you can get up to 3 quick shots to his body before he flies back up to his perch. Shoot him in the head again, and repeat the rest of the process until he drops the sword. Shooting him like this is a lot easier than trying to shoot his constantly moving tail from the bridge.

Melee Option
A melee alternative is to get 10 to 20 arrows and a spear-type weapon, preferably halberd since it has high attack early on in the game. Go below the bridge where the dragon is sitting and look for his tail hanging out. Time it just right and you can hit the dragon's tail. When he flies towards the side of the bridge equip your halberd in both hands and press R2 for a strong spin attack. If you hit him, you'll see blood coming off of the tail. Repeat until a window comes up saying that you have obtained the Drake Sword.

Killing the drake
Note : You want to get the Drake Sword first.

Although the drake does not have to be killed and can be avoided, killing it rewards 10,000 souls as well as the drake sword. Clearing the dragon will also give easy access to the two items located on the bridge, which are a Claymore sword and a Soul of Nameless Soldier, as well as access to a bonfire and a shortcut gate that leads to the undead parish. Methods for killing it are basically the same as those above for getting the sword to drop but repeated until the dragon is dead. The dragon heals once its HP drops 25% by enfolding its wings over its body. It is possible to continue shooting arrows and doing damage while the wings are folded over it, but it will still out-heal this damage.. Lower level characters may be unable to kill the dragon at all due to the dragon's ability to out-heal the damage being done.

One shot one kil
Note : This is an apparent glitch that may be patched at some point.

You can kill the dragon with ONE arrow. Climb the ladder from the rat's nest and turn left to climb the spiral stone staircase. Don't go to the right into the Undead Parish. At the top of the tower is a Black Knight so be careful and kill him first. Once at the top of the tower, go to the broken edge on the tower where you should easily be able to see the dragon. Aim down and left and shoot the dragon. The dragon will roar and fall through the bridge and die when it apparently hits bottom somewhere.. You can wait on top of the tower or start going back down to the rat's nest and shortly you will hear the dragon dying whoosh sound and be given 10,000 souls. If you have not already gotten the Drake Sword, you can no longer get it this playthrough from the Hellkite Dragon.

If the Dragon is not visible when you try this atop the tower, some users have been able to get him to reappear. Go to Firelink Shrine and use the bonfire. Then return to see if the Dragon is visible, but do not use the bonfire in Undead Burg first. If this does not work and he is still not visible, return to Firelink, use the bonfire and then go down the steps and use the elevator that takes you to New Londo. If possible, go to the Valley of the Drakes from here and then use the back entrance into Blighttown. Kill some foes and then backtrack to Firelink and again to the Dragon without stopping at bonfires on the way. This has been confirmed as a way to make the Dragon reappear.

Killing the Dragon as a Caster
Obtain any kind of bow that you want, even if you don't meet the requirements for it, and get some arrows. Shoot him from under the bridge to get rid of the enemies on top. At this point, go to the bridge access stairwell, and shoot him from around the top of the stairs. This will cause him to come land on the bridge. While he is landing he is defenseless, so you can charge up a heavy soul arrow as he's coming down and lock on as it's about to fire. Roll down the stairs and wait at the bottom. He will fire breath and fly back up to his perch. Rinse and repeat and soon the sweet taste of victory will be yours.

Killing the Dragon in Melee
It is possible to kill the dragon (almost) entirely by melee, using a variation on the homing soul arrow strategy. It is highly recommended lower levels farm the Drake Sword by shooting the tail from under the bridge first (buy a short bow and a couple dozen arrows), as it does high base damage and only needs 16 str/10 dex. Once that's done bring 20-30 arrows and a bow. Stand at the top of the stairs and aim at the dragon. Fire an arrow then immediately switch to your melee weapon while running out to the bridge. Use a fast swing (I prefer the 1-handed R2 attack with the drake sword) to hit where his head will land. Follow up if you're feeling confident then roll back toward the stairs. If he does the head swipe you should dodge it safely. The foot stomp is too fast and will often land, but should provide you enough time to escape. The near instant fire breath is a hazard, but is weaker than the normal long attack so you can survive it with 12 vitality or less. Sometimes he'll do two instant fires in a row and kill you anyway. If you die and want to save souls, just fire an arrow as normal then touch the blood stain and escape. Also note that occasionally an arrow will draw a long flame attack rather than immediate landing. This is a slow attack however and should allow ample time to escape to the stairs. I was doing 159 damage per attack (280 per double-tap) and outpaced his healing easily at level 16.