Aquatic Scourge

Type	Boss – Burrowing Enemy
Environment	Sulphurous Sea
AI Type	Aquatic Scourge AI
Damage	0 (Passive); 65 / 104 / 128 / 136 (Contact); 60 / 100 / 120 / 132 (Tooth)
Max Life	73,000 / 116,800 / 136,000
Defense	35
DR	10%
KB Resist	100%
Inflicts debuff	Irradiated 100% chance
Debuff duration	3 seconds
Debuff tooltip	Your skin is burning off

Type	Boss – Burrowing Enemy
Environment	Sulphurous Sea
AI Type	Aquatic Scourge AI
Damage	0 (Passive); 80 / 176 / 187 / 198 (Contact); 60 / 100 / 125 / 143 (Tooth); 56 / 92 / 116 / 128 (Sand Blast); 66 / 112 / 128 / 140 (Sulphur Cloud)
Max Life	73,000 / 116,800 / 136,000
Defense	20
DR	5%
KB Resist	100%
Inflicts debuff	Irradiated 100% chance
Debuff duration	6 seconds
Debuff tooltip	Your skin is burning off

Type	Boss – Burrowing Enemy
Environment	Sulphurous Sea
AI Type	Aquatic Scourge AI
Max Life	77,000 / 123,200 / 147,200
KB Resist	100%
Immune to
Coins	15

If you were looking for something other than the Aquatic Scourge, see Scourge (disambiguation).

"A horror born of pollution and insatiable hunger..."

The Aquatic Scourge is a boss that can be fought in the Sulphurous Sea biome at any point in the game, but is intended to be fought during Hardmode. Being the hydrated and mutated version of the Desert Scourge, it possesses similarities in its drops but significant differences in its behavior.

Spawn

The Aquatic Scourge spawns naturally, albeit rarely, in the Sulphurous Sea. It can be summoned manually by using the Seafood at any time.

Segments

Aquatic Scourge BodyAlternate

Statistics

Type	Boss – Burrowing Enemy
Environment	Sulphurous Sea
AI Type	Aquatic Scourge AI
Damage	0 (Passive) 55 / 88 / 112 / 120 (Contact) 56 / 92 / 116 / 128 (Sand Blast)
Max Life	73,000 / 116,800 / 136,000
Defense	25
DR	10%
KB Resist	100%
Inflicts debuff	Irradiated 100% chance
Debuff duration	3 seconds
Debuff tooltip	Your skin is burning off

Aquatic Scourge Tail

Statistics

Type	Boss – Burrowing Enemy
Environment	Sulphurous Sea
AI Type	Aquatic Scourge AI
Damage	0 (Passive) 45 / 72 / 96 / 104 (Contact)
Max Life	73,000 / 116,800 / 136,000
Defense	45
DR	15%
KB Resist	100%
Inflicts debuff	Irradiated 100% chance
Debuff duration	3 seconds
Debuff tooltip	Your skin is burning off

Behavior

The Aquatic Scourge is an aerial worm-like enemy, with 31 / 36 / 41 / 51 segments in total. Once spawned, the Aquatic Scourge will be passive, slowly following the player. It will become hostile and rapidly accelerate upon being hit by the player and dropping to 99% health or lower.

Once hostile, the Aquatic Scourge will follow the player with curve-like movements with a constant speed. As it travels, it will release many different projectiles along its path.

The Aquatic Scourge enrages outside the Ocean and Sulphurous Sea, greatly increasing its movement speed. The boss will only enrage once the player has left both biomes.

Attacks

The Aquatic Scourge randomly releases Sand Blasts and homing Sand Teeth from its tooth-less and toothed body segments respectively.
When at 75% health or lower, every 7 / 6 seconds, the Aquatic Scourge vomits out several projectiles from its mouth in a circular spread. These projectiles include:
- 20 / 30 Sand Blasts in an evenly-spaced ring which travel quickly in a straight line.
- When at 50% health or lower, 7 / 14 Sand Poison Clouds in random directions and speeds that linger in the air for 30 seconds.
  - Additionally, it will stop firing Sand Blasts and Sand Teeth from its segments for the duration of this phase.
When at 25% health or lower, it will proceed to fire from its segments again and stop vomiting Sand Poison Clouds, all Sand Blasts during this phase are homing.

In Expert Mode

Segments are increased from 31 to 36 and size increased by 10%.
Toothed body segments fire Sand Teeth more often.
Releases 7 more Sand Poison Clouds and 10 more Sand Blasts in the vomit attack.
Increased cloud spread, top speed, and acceleration as health lowers.

In Revengeance Mode

Segments are increased from 36 to 41 and size increased by 5%.
Moves faster and has a higher top speed.
Vomits more often and Sand Blasts resulting from the vomit travel faster.
When it is not submerged in liquid, every 11 seconds, the Aquatic Scourge performs a circle around a certain point at its path for 2 seconds before charging the player.
- The Aquatic Scourge will turn a brownish color over time to telegraph the dash, this timer can be reset if it is submerged in liquid.
- While spinning, it fires 3 barrages of 3 / 5 sand blasts at the player.
- It can not vomit while performing this attack.

In Death Mode

Segments are increased from 41 to 51 and size increased by 5%.
Acceleration and top speed increase depending on the player's distance from it and as its health decreases.
Sand Blasts and Teeth travel even faster.
Fires a wider spread of 5 sand blasts while spinning.

During the Boss Rush

Does not have a passive nor an enrage state.
Vomits every 5 seconds instead of 7 / 6.

Aftermath

Anthozoan Crabs, Baby Flak Crabs, and Belching Corals will begin to spawn in the Sulphurous Sea.
The second tier of the Acid Rain and all of its associated Content will become available.

Resistances

Aquatic Scourge is weak to fire debuffs, but resistant to sickness debuffs.
All segments take reduced damage from non-minion piercing projectiles in Expert Mode. Projectile damage is divided by the number of times it pierces. Infinite piercing deals 50% damage.
All segments reduce damage from grenade-type projectiles by 80%. A list of affected projectiles is below.

Resisted grenades
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Additionally, all segments take:
- 90% damage from the Hell Burst.
- 75% damage from the Hydraulic Volt Crasher.
- 50% damage from the SHPC's explosions and the Dormant Brimseeker.
- 10% damage from the Brimstone Sword's explosion.
  - In addition, the pierce on the explosion is updated to 2 once it hits a segment.

Notes

The player is allowed to use a Magic Mirror or Recall Potion if Aquatic Scourge is passive.
Aquatic Scourge, like Desert Scourge and The Leviathan, can drop fishing items rewarded by the Angler for completing his quests.
All of the Aquatic Scourge's loot will spawn at the nearest segment with the exception of the Sulphurous Sand and Hearts, which will always spawn at the head.
All minions cannot do damage to the Aquatic Scourge while it is above 99% health. (Except for Luxor's Gift summoner projectile)
Killing the Aquatic Scourge in pre-hardmode will cause the hardmode variant of Acid Rain to take place, granting the player access to hardmode weapons and equipment early.

Tips

For more elaborate strategies on defeating the Aquatic Scourge, including weapon and arena recommendations, see Guide:Aquatic Scourge strategies.

This fight is very difficult to tank. Avoid the tooth projectiles and gas clouds at all costs and use weapons with ranged options if possible.
Avoid the head as much as possible, especially on Revengeance or Death Mode, as its high contact damage can kill the player extremely quickly.
Spawning the Aquatic Scourge when trying to fish in the Sulphurous Sea is a good idea, as it strongly reduces enemy spawn rate while it is alive. Due to the time-consuming nature of fishing or waiting for the Scourge to spawn, it is highly likely that it will spawn while the player is fishing.
While the Aquatic Scourge can spawn in Pre-Hardmode, it is not recommended to fight it until the player has acquired decent Hardmode gear since it is very fast and has many attacks that an early game player cannot handle.

Trivia

The theme heard during the Aquatic Scourge battle is Outcast of the Sulphurous Seas, which was composed by the artist DM DOKURO.
- The theme is a remix of the Desert Scourge’s theme.
- If the Calamity Music add-on mod is disabled, Boss 2 will play instead.
Because it is a more powerful version of the Desert Scourge, many of their drops are shared. The Aquatic Scourge's weapons are upgraded versions of the Desert Scourge's weapons, as well.
- This boss and the Desert Scourge can both drop several fishing drops, making them the only two bosses to share a drop outside of crafting materials, potions, or fishing items.
The Aquatic Scourge's design was initially a redesign of the Desert Scourge made by Frous, a spriter for the mod.
With a passive state longer than that of Crabulon's (the Scourge will always remain passive unless attacked, Crabulon will wait a while before attacking) and it slowly following the player, then rapidly accelerating when attacked, it could be postulated that the Aquatic Scourge has some degree of intelligence or sapience and is simply curious about the player.
Similarly to Leviathan and Anahita, the Aquatic Scourge can be accidentally summoned in Pre-Hardmode, although the latter will not be immediately hostile.
The Aquatic Scourge was previously an alternative for The Twins because of its previous ability to drop Souls of Sight.
If the Boss Checklist Mod is installed, its unique despawn message will be "The Aquatic Scourge swam back into the open ocean."

Lore

The long-lost relative of The Desert Scourge mutated by the toxic sulphuric waters above the Abyss. Due to its adaptations to thrive in the sulphuric ocean and ample food supply of catfish and flounder it is far less aggressive than its relative. Those that venture to the sulphuric ocean should exercise caution however, as this sea beast is still a carnivorous predator and will immediately attack if provoked.