Guthix dragon

The Guthix dragon is a powerful dragon created by Guthix himself. It served as guardian for Guthix's altar which is located at the end of the the Undergound Pass of Lumbridge. It currently guards the Amulet of Life, which was created by Guthix. This amulet is extremely powerful, so naturally Guthix used one of his most powerful servants to protect it. The dragon is nearly impossible to kill as it hits very accurately and frequently does its max hit. The dragon gives the best possible drops from any monster in runescape, but it can only be killed once.

History
When Guthix found out that other gods like Zamorak and Saradomin where destroying what he made (Gielinor), He had made an undergound maze so that he could pray at his altar. Behind the altar, he had a treasure chest which held the priceless Amulet of Life. Guthix knew that if anyone got past the maze, they would steal the amulet, so he went to the wilderness, the place where his brothers had destroyed the land. There, he found a green dragon, therefore, he picked this colour, it was the color of his symbol. The first time he tried to cage it, it bit his hand, then guthix punched the ground so hard that he made a shallow hole, then found out that he wouldn't hurt himself trying to cage the dragon because he had found an energy source. So, he caged the green dragon then after coming back to his altar, he did an enchantment to the green dragon, making it 30 times more powerful than the regular green dragon. After a few moments, Guthix ordered the dragon to guard his altar and the Amulet of Life.

Weapon use
You are given a dragon stun-battleaxe, or get Diamond bolts (e)(b), or have the staff of earth with 500 blood runes and 2500 air runes. At the end of the quest the Duke will take whatever is left of the bolts and runes and take the staff and battleaxe.

Melee:
headslot: Guthix full helm>torva full helm>Torag's helm>helm of neitiznot>Dragon med helm

neakwear: Amulet of glory>amulet of fury

Torso: Guthix platebody>Torva platebody>Dharok's platebody>bandos chestplate>dragon chainbody

cape: Completionist cape>max cape>Skill cape (t)>Obsidian cape

wrist/hands: barrows gloves>dragon gloves>rune gloves>combat bracelet

Ring: berserker ring (i), warrior's ring (i)

shield: Guthix shield>Chaotic kiteshield>Divine/Arcane/Elisyan/Spectral spirit shields>dragonfire shield>Dragon sq shield

legs: guthix platelegs>torva platelegs>Dharok's platelegs>bandos tasselets>Dragon platelegs/skirt

Boots: Dragon boots>rune boots>Bandos boots

Ranged:
headslot: Guthix coif>pernix cowl>Armadyl helm>third-age coif>Robin hood hat>Karil's coif>black d'hide coif>full slayer helm

Neckwear: Amulet of ranging>amulet of glory>amulet of fury

Torso: Guthix body>Pernix body>Armadyl chestplate>third-age body>karil's leathertop>Black d'hide body

Cape: Completionist cape>max cape>skill cape (t)>Ava's Attractor>ava's accumulator>ava's alerter

Wrist//hands: Guthix vambraces>mercenary gloves>barrows gloves>dragon gloves>black d'hide vambraces

Ring: archer ring (i)>ring of vigor

Shield: Eagle-eye kiteshield>Divine/Arcane/Elisyan/Spectral spirit shields>dragonfire shield

legs:Guthix chaps>pernix chaps>Armadyl chainskirt>third-age chaps>Karil's skirt>Black d'hide chaps

Boots: Ranger boots>snakeskin boots

Magic:
It is not recomended to fight with magic, but if you choose to, than it's recommended that you use the Guthix vestment set.

Getting to the Underground Pass of Lumbridge
To get there, you must talk to the Duke Harico to start the quest, Guthix's Altar. If you don't start the quest, when you go to the entrance of The Undergound Pass of Lumbrige, you will get a message saying "There might be scary monsters down there, maybe I shouldn't go." After talking to the Duke, you first go behind the Lumbridge castle. Then you will see the Guthix's symbol very faint on the castle and a hole shaped as Guthix's symbol. But before you go down, ask the duke for a full guthix (requiring 40 defence) or guthix d'hide set (requiring 40 defence and 70 ranged) because that's how you can get your hands on the Amulet of Life. Also, ask The Duke for a Dragon-stun battleaxe/Diamond bolts (e)(b), or items for earth wave. Using poison is a waste of time, as the Guthix Dragon is immune. If you use any weapon other than the Dragon-stun battleaxe, Diamond bolts (e)(b), or earth wave, you will constantly hit zero's. Even the powerful Void sword is useless agaist this beast.

Drops
The dragon can only be killed once

NPC
After finishing Guthix's altar, the guthix dragon will become a NPC, selling guthix items and will reveal his name, Antheros. The player doesn't actually kill the dragon, after the dragon reached 300lp or less it stops attacking the player and forfeits the fight. After that the dragon becomes a NPC.See guthix dragon (NPC)

Trivia

 * After giving the Duke the Amulet, you get to keep the Dragon-stun battleaxe, the whole guthix armor set, an anti-dragonfire shield, 40000 XP for defence, attack, strength, constitution and 130K coins.
 * The dragon can only be killed once!
 * The dragon has a very rare chance of dropping the Guthix dragon egg which requires a Summoning level of 99 to achieve as a drop. Only a very few amount of people have actually found the egg, since its a very rare drop and the dragon can only be killed once.
 * The dragon is both a monster and an NPC