Araxxor

Araxxor is an enormous araxyte spider who lives in the Araxyte lair beneath the Haunted Woods. He is the most difficult solo boss in RuneScape. He can be fought alone or with a friend, although he is considerably stronger if fought with a friend. His drops include components for three level 90 two-handed weapons, one for each combat style, along with a new pet, with multiple skins to be unlocked for the pet through achievements.

One can influence the flow of the battle oneself; Araxxor's lair has three main tunnels and each path triggers different fight mechanics. In order to trigger different fights, players need to burn a web and wait one minute before proceeding. Also, when there are two people fighting instead of one, Araxxor's attacks are "doubled". This includes minion spawns and its strength in general.

According to Mod Chris L, Araxxor has 23 different mechanics, which is much more than Vorago.

Starting a fight
Araxxor is located in a cavern south-east of Port Phasmatys called the Araxyte lair. The cavern can be accessed by using the shortcut on the southern wall (requires 92 Agility) or by accessing the western gate.

Just like the God Wars Dungeon or Vorago, there are 2 ways to start a fight; with or without an instance.

The instance will cost 200,000 gold for each attempt of killing Araxxor. Players will also have the choice of not paying the instance, and only 1 or 2 players can fight it at a time.

Only one person or duo can enter the base world instance at a time. If someone is inside, you will not be able to enter and will have to pay the 200,000 coin instance fee in order to fight Araxxor on the same world.

To save money, one player can start an instance and wait while somebody else kills the boss. As long as only one person is in the arena at one time, the fight will still be the single player version. After the second player completes the fight, they can re enter the instance and get the full hour's worth. It's also possible to alternate kills with another player as long as one person stays in instance at all times.

Fight overview
Araxxor has 3 paths which you can take, however, only two paths will be open in a given cycle (the two blocked by webs rather than rocks). The path you chose decides the order of the mechanics Araxxor uses, as during the third phase of the fight Araxxor will utilize a variation of the other unlocked path's mechanics.

Araxxor's first phase starts in a large room, with Araxxor having 100,000 LP. There are two available tunnels blocked by giant webs, and the player must pick a tunnel, and light the web in front of it. The web takes 1 minute to burn down, and the player must fight Araxxor until the web has been burned down. Once you pick your path, that is the path you have decided on and you cannot change your mind until the fight is over. Araxxor will not die in phase 1 even if you deplete all of his health, and he will be healed 5000 LP every time his health is depleted. Therefore the only way to proceed is moving onto phase 2 through one of the available paths. Moving beyond the burnt web will automatically start phase 2 regardless of how much LP Araxxor has left from phase 1 and his health will replenish back to 100,000 LP once phase 2 begins. The condition to proceed to phase 3 from phase 2 varies depending on the path chosen.

Similarly, it is possible to proceed to phase 3 without depleting all of Araxxor's health during phase 2 and again his health will instantly replenish back to 100,000 at the start of phase 3. However, any 'leftover' health which you did not deplete from Araxxor during phase 1 and 2 will be carried over to phase 3-Araxxor will regenerate any leftover health from phases 1 and 2 when he's damaged during phase 3. This means it is highly advisable to damage Araxxor as much as possible in phase 1 at least as phase 1 is much easier than phase 3.

Araxxor, like Vorago, cannot be killed until all of the phases have been finished and the requirements met. This also means that players cannot leave except through victory or death, as they cannot teleport from the arena.

The fight's fourth and final phase is on a platform where you are challenged and must kill Araxxor's mate; Araxxi.

If you die, your grave will appear in the graveyard which can be reached by right-clicking the Araxxyte cave.

Strategies
It should be noted that the more times you successfully kill Araxxor, the more angry he gets and begins to have increased damage. This "anger" resets every day at 00:00 UTC.

Drops
Araxxor himself does not reward any drops. Instead, they come from the corpse of Araxxi, the spider that replaces Araxxor in the final phase of the fight. The corpse functions identically to the Queen Black Dragon's reward chest, and as such items may be sent directly to the bank from it, put into a player's inventory, or discarded. It will reward players with arrows on every kill, in addition to 2 other drops and sometimes 10-20 charms. Its unique drops include the parts needed to make level 90 two-handed weapons and a pet that has unlockable skins. For a full list, see Araxxi's page.

Trivia

 * As a teaser on the day of Araxxor's release, Jagex Moderators changed their player model to the same as Araxxor and infected other players into baby spiders by using its cleave attack in places such as the Grand Exchange.
 * Similarly, they held a community event on the day prior, doing much the same thing, however, on the air.
 * "Hoobs" was the first player to kill Araxxor solo, and this was announced using a worldwide news feed.
 * Araxxor's mechanics are similar to a number of other monsters in RuneScape:
 * Its cleave attack is similar to General Graardor's attack when he is fought during The Mighty Fall. If players are not within melee distance of Araxxor, it will also drag them to it, similar to Nex's magical drag.
 * Players also leave by an egg, which is similar to that of leaving the Borehole with the orb after killing Vorago.
 * On the final phase, if a player tries to protect/deflect an attack from Araxxi, it will use another combat style instead, similar to fighting Revenants. Prayer switching is also one of the best ways to beat this phase, similarly to TzTok-Jad.
 * Players must avoid the highly acidic wave Araxxi releases, similar to that of avoiding the Dark energy core the Corporeal Beast sends out, although the acidic wave does not always follow the player.
 * Like the Kalphite King, Araxxor comes in a different form of combat. It also has a form of its instant-kill with the acidic spider that bursts from the ground.
 * Like the Kalphite King/Queen Black Dragon, Araxxor has minion assistance during the fight, although the minions Araxxor has cover the whole combat triangle and have some support spiders, while the minions the King has use magic and the ones the Queen has uses melee/magic.
 * Araxxi's damage increases as her lifepoints decreases, similar to that of Dharok the Wretched.
 * Due to player complaints on parts of the Araxxor fight, Jagex changed the following:
 * If players take the middle path and are teleported to Araxxor when he does his cleave attack, they will no longer get transferred to an invalid tile.
 * Araxxor will no longer spawn an acidic spider underneath him.
 * The acidic spider that destroys graves no longer appears in the graveyard.