Son of Arachna

Last updated: Exalt Version (Dec 2020)
Son of Arachna

The Son of Arachna is the boss of The Crawling Depths.

The Realm Eye says:
Arachna birthed thousands of daughters in her den, but only her very first child was a male.
At first, the spider queen took great pride in her son’s might, but he soon became a threat to the rest of her children.
He was banished by his mother, left to fend for himself in the wild and create a family of his own.



Base HP: 40,000 (Boss Adaptive Scaling Boss Adaptive HP Scaling)
DEF: 30
EXP: 15,000
Location: The Crawling Depths

Immune to Stasis
Immune to Paralyzed

Quest Boss
Counts towards God Kills
Counts towards Beast Kills

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Condition effects
Speed (tiles/sec)
Range (tiles)
Venom Spike
Piercing Shots hit multiple targets
Venom Blob
Weak Icon Weak for 5s
Piercing Shots hit multiple targets
Green particle trail
Arachna Star
Lifetime: 5s
Piercing Shots hit multiple targets
Purple Spider Venom
Grey Down Arrow Exposed for 4s
Parametric Shots are parametric
Magnitude: 4
Lifetime: 7s
Piercing Shots hit multiple targets
Faces Direction
Red Spider Venom
Blood Drop Bleeding for 5s
Piercing Shots hit multiple targets
Armor Piercing Ignores defense of target
Blue Spider Venom
Word Bubble Quiet for 3s
Wavy Wavy shots
Piercing Shots hit multiple targets
Faces Direction
Green Spider Venom
Red Down Arrow Slowed for 4s
Piercing Shots hit multiple targets


The Son of Arachna is found in a circular room with four giant eggs and many smaller blue eggs that spawn a type of spider when destroyed. When activated, it will spawn a number of Epic Arachna Elements that form a web of slowing threads, before attacking.

Phase 1

The Son of Arachna will loosely chase players, firing rings of green arrowheads and single fast green orbs that inflict Weak. Depending on how many of the four large eggs are active, the boss will gain additional attacks and status effects (with each egg displaying the respective status it gives the boss).

  • If the Green Egg is alive, the boss will fire additional spreads of Slowing green bullets, and will be permanently Speedy, increasing its movement speed by 50%.
  • If the Blue Egg is alive, the boss will fire additional rings of wavy blue shots that Quiet, and will be permanently Energized, letting it occasionally spawn large spider minions.
  • If the Silver Egg is alive, the boss will occasionally fire multi-directional parametric purple shots that inflict high damage and Expose, and will be permanently Armored, increasing its DEF by 50%.
  • If the Red Egg is alive, the boss will frequently fire additional 2-way shotguns of red Bleeding bullets, and will be permanently Damaging, making all its attacks pierce armor.

The boss is invulnerable until one of the four eggs is destroyed, upon which all other eggs will become invulnerable until later phases. However, a random one of the four eggs will always be covered in webs and invulnerable until the end of the fight. When an egg is destroyed, it will release a large number of the respectively colored Crawling Spiders.

Note that the first egg can be destroyed without activating the boss if the player takes care to not get too close to it, although the boss will immediately activate afterwards if that is the case.

Every time the boss loses 25% of its HP, it will change phases, go invincible, and expose the eggs again, meaning that an egg must be destroyed each phase to advance the fight. Which attacks it uses and which buffs it will have in each phase can be altered by managing the order in which the large eggs are destroyed, as well as randomly depending on which egg is invulnerable.

Phase 2

The Son of Arachna circles around the web while firing the above pattern, alternating between different orbit distances. The Epic Arachna Elements will also begin firing single aimed web shots that inflict Slowed.

Phase 3

The Son of Arachna starts picking Arachna Elements at random and charging towards them, leaving a trail of Spider Stars in its wake. When reaching the web spoke, it will circle it briefly, rapidly firing green orbs, before moving to another random spoke. Its colored attacks will switch to radial spirals from this point onwards.

The Epic Arachna Elements will also start periodically using red threads that inflict armor piercing damage instead of Slowing players.

Phase 4

The Son of Arachna starts circling around the room at a much faster speed, rapidly firing its radial attack and whatever colored attack it has left. It will periodically stop at the room’s corners to fire a dense spiral of green orbs.

The last egg, which was previously covered in webs, becomes uncovered and vulnerable. When its last egg is destroyed, it will start using its original firing pattern, chasing players if they’re too far but fleeing from them if they get too close.


Epic Arachna ElementEpic Arachna Element

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Tips and Strategies

It is highly recommended to eliminate the first Giant Egg Sac before activating the boss, as it’ll effectively allow players to skip a phase of the fight and get straight to doing damage. If you have subpar stealthiness and don’t want to deal with the small spiders, eliminating the small eggs surrounding the arena before engaging the boss can be helpful. Note that neither of these are likely to occur in larger, disorganized groups, who are liable to run in and activate the boss prematurely.

When defeating the giant eggs, keep an eye on the order in which they are destroyed. The first eggs to be destroyed should be the ones that give the boss abilities that you have a harder time dealing with - however, note that the order isn’t always in the players’ control, considering one at random cannot be hurt until the final stage. The passive abilities the eggs provide are usually more dangerous than the shots they let the boss use, so crippling key abilities is a good way to make the fight easier:

  • Destroy the Green Egg to cripple the boss’ mobility.
  • Destroy the Silver Egg to shred the boss’ defenses.
  • Destroy the Red Egg to reduce the boss’ damage.
  • Destroy the Blue Egg to stop the spawning of large spider minions.

Try not to walk into the web too much. The Son of Arachna deals massive damage with each bullet, and not being able to move out of the way in time can be fatal. When the web threads turn red, their damage can seem negligible at first, but it can very easily build up if you stay in it for too long.

The boss follows several very distinct movement patterns and rarely moves erratically. Keep an eye on its movement patterns to reduce the risk of being sat on and instakilled.

In its final phase, the Son of Arachna gains a massive speed boost and starts circling the map rapidly while spewing out lethal bullets. This is arguably its most deadly phase if it takes a player off guard, so be prepared to react once you push it into its final phase. However, this phase is also the shortest out of all of them, as it ends instantly once you destroy the final Giant Egg.

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Prior to Exalt Version (Dec 2020), the Son of Arachna’s sprite was as shown below:
Son of Arachna (old)

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