Polterghast is a post-Moon Lord boss that can be fought in the Dungeon. It is notable for being the only optional post-Moon Lord boss. However, given the strong equipment that it grants access to upon its defeat, it is highly recommended to fight it before challenging The Devourer of Gods.
Summoning[edit | edit source]
Polterghast can be summoned by using a Necroplasmic Beacon in the Dungeon. Alternatively, if it has not yet been defeated in the world, it will spawn after killing 30 Phantom Spirits, which can be found in the Dungeon after Moon Lord has been defeated. After defeating it once, using a Necroplasmic Beacon becomes the only way to summon the boss.
Behavior[edit | edit source]
Polterghast’s behavior is similar to Plantera, chasing the player quickly while using four long appendages to grapple blocks. In later phases, however, these appendages will detach and begin firing projectiles independently. Polterghast will enrage if the player moves onto the Surface.
Phase 1 (Polterghast)[edit | edit source]
- Polterghast follows a Plantera-like behavior, placing its hooks on nearby walls to pull itself towards the player.
- While chasing the player, Polterghast steadily fires fast-moving blue projectiles which bounce off of walls.
- Transforms into Necroghast at 75% health.
Phase 2 (Necroghast)[edit | edit source]
- Necroghast's hooks detach from their chains, and they begin independently moving and shooting ghostly projectiles at the player. The hooks no longer deal contact damage.
- Necroghast moves more quickly and deals more melee damage.
- Necroghast's projectiles are now red instead of blue. Red projectiles travel faster, further, and deal slightly more damage. It also shoots bigger wall-piercing projectiles that slightly home into the player.
- Transforms into Necroplasm at 33% / 50% health.
Phase 3 (Necroplasm)[edit | edit source]
- Necroplasm's hooks move slower and less often. The chains reappear and the hooks no longer shoot projectiles.
- Necroplasm moves significantly faster and deals even more melee damage.
- Necroplasm stops firing projectiles directly. Instead, it summons three invincible Phantoms which slowly revolve around the player. The Phantoms fire spirit orbs which are initially slow, but quickly accelerate toward the player.
- Necroplasm summons a weaker clone of itself. The clone behaves similar to Necroplasm, staying within the hooks. It alternates with Necroplasm in chasing the player. Necroplasm will summon a new clone 10 seconds after the previous is killed, and only one clone can exist at a time.
- While the clone is alive, Necroplasm's DR is boosted by 60%.
- While the clone is dead, Necroplasm is always moving at full speed.
- When below 20% / 33% health, Necroplasm begins summoning Happy Phantom Spirits, which also fire ghostly projectiles at the player.
- When below 5% / 10% health, Necroplasm begins to move more quickly as a last-ditch effort to attack the player, and will also stop summoning Happy Phantom Spirits.
In Revengeance Mode[edit | edit source]
- Polterghast is faster in all three phases.
- Transitions into Phase 3 (Necroplasm) at 50% health instead of 33%.
- Spawns Happy Phantom Spirits at 33% health instead of 20%, and spawns even more of them.
- Moves much faster at 10% health instead of 5% health.
- Phantoms shoot more often.
In Death Mode[edit | edit source]
- Phantoms Spirits shoot at an even higher frequency.
Summons[edit | edit source]
Aftermath[edit | edit source]
- The Mauler will begin dropping the Sulphuric Acid Cannon.
- The Colossal Squid will begin dropping Calamari's Lament.
- The Reaper Shark will begin dropping Reaper Teeth, the Valediction, Deep Sea Dumbbell, and The Reaper.
- The Juvenile Eidolon Wyrm will begin dropping the Eidolic Wail and the Soul Edge, and the Adult Eidolon Wyrm will begin to spawn naturally.
Notes[edit | edit source]
- Polterghast's damage reduction works differently from other bosses. Ichor reduces its DR by 12%, and Cursed Inferno reduces its DR by 10%.
- This reduction is multiplicative. As such, when under the effects of Ichor, DR is 8.8% in Phase 1, 13.2% in Phase 2, and 17.6% in Phase 3. When under the effects of Cursed Inferno, DR is 9% in Phase 1, 13.5% in Phase 2, and 18% in Phase 3.
- Polterghast's clones do not show up on the map. Because of this, it is easy to run into the clone when it is off-screen and the player is moving fast.
Tips[edit | edit source]
- For more elaborate strategies on defeating Polterghast, including weapon and arena recommendations, see Guide:Polterghast strategies.
- Polterghast has similar AI to Plantera, which means that movement strategies used during that boss fight may work here as well.
- Ark of the Elements is a great weapon against its first and second phase, however the weapon becomes very ineffective when it reaches the last phase. At that point, it's recommended to switch to weapons that can deal enormous damage on one hit, such as the Blissful Bombardier.
- Don't rush too much when fighting its last form. The chaotic activity can easily overwhelm the player if they're careless. Take your time and be careful when dodging.
- Oddly, Polterghast is slowed in water, allowing the player to encase a certain area and use the Abyssal Diving Suit to their advantage.
Trivia[edit | edit source]
- Polterghast's theme is Feral Amalgamation, which was made by the artist DM DOKURO.
- Before the update which allowed players to fight bosses more freely was released, it was required to beat Polterghast, as the Ruinous Soul was required to craft the Cosmic Worm.
- Despite being a boss, it doesn't have a Boss Mask.
- The boss’ multiple names are the result of a sort argument between the spriter, LordMetarex, and the lead developer, Fabsol, also known as MountainDrew. The spriter was naming his files ‘Necroplasm’ and was using it as the official name for the boss. During a spoiler, the official name was revealed to be ‘Polterghast’. After an argument the developer decided to use ‘Polterghast’ for the first phase and ‘Necroplasm’ for the last phase. ‘Necroghast’, being a combination of the two names, was used for phase two.
- In the mod's source files, Phantoms are referred to as 'PhantomFuckYou'.
Lore[edit | edit source]
Over the course of Yharim's conquest over the world, countless people perished - whether killed by his forces, imprisoned and fed alive to his monsters, or struck down by Yharim himself. Few died peacefully, and many cursed the Jungle Tyrant's name with their last breath. Some found peace in their afterlife; others lingered in the physical realm as phantoms, their hatred and anguish immutable even by death.
The Dungeon served as Yharim's prison during his rule - and for the less fortunate, his torture and execution chambers. Attracted to the bloody reek of pain and death, the restless spirits flocked to the Dungeon in droves, possessing the corpses of the deceased and animating armors and weapons. Though easily dispatched at first, their numbers grew and grew - seemingly without end as the death toll of Yharim’s reign continued to rise. Deeming the Dungeon a waste of his men and resources, he withdrew them and left the dead to rot.
As spirits clinging to reality through little more than hatred, they held no loyalty to their fellow dead. Many swiftly turned on each other - souls devouring souls in an instinctual bid for power. As lesser souls grew swift and elusive, the first souls to feed continued to fight and consume one another until a legion took form, lacking even the concept of predator and prey. Hatred for the one that first slew them and a desire for more that could never be satisfied; reduced from countless living men to a mindless beast, nothing else drove the amalgamation now.
Scraping fragments of metal into patchwork armor and animating broken chains with its essence to better hunt its lesser brethren, the Polterghast roams the depths of the Dungeon away from prying eyes. It continues to feed and fester in the darkness until it feels the power of the object of its collective hatred once more...or until it detects one whose power has begun approaching the point of indistinguishability.