Polarities Mod/Esophage

The Esophage is a Hardmode boss, intended to be fought after the mechanical bosses alongside Plantera.

While it is alive, its exclusive Necrosis will play; if the Polarities Mod Music sidemod is not enabled, the vanilla track Boss 2 will play instead.

Spawn
The Esophage will automatically spawn after clearing, but can also be fought manually on its own afterwards with a. It can only be summoned in the Corruption or Crimson.

Behavior
Esophage walks steadily towards the player, moving faster if the player gets too far away, and gaining a boost in speed as its health lowers.

Esophage's crimson head and corrupt capsid each have their own set of attacks. Neither section will repeat the same attack twice in a row. The head uses the following attacks: The capsid uses the following attacks:
 * Ichor Rain - The boss shoots a jet of ichor projectiles almost directly into the air, which falls back down in a wall that moves towards the boss.
 * Scythe Slashes - Esophage's mandibles will slash at the player four times in rapid succession, each creating a set of projectiles with a narrow spread that start off near-stationary but rapidly accelerate.
 * Flesh Chunks - The boss vomits six flesh chunks directly downwards, which aggressively bounce and roll after the player before exploding into gravity-affected teeth.
 * Capsid Plates - The capsid opens up and shoots 20 capsid projectiles, which quickly move to form a shrinking ring around the player. Ten of these projectiles will always be greyed-out shadowy fakes that do no damage.
 * Phage Tendrils - The boss shoots six dark tendrils from its capsid which briefly home in on the player.
 * Cursed Fireballs - The capsid opens up and shoots four cursed fireballs in succession, each targeting the point the player was at a second ago before exploding.

Above 2/3 health, the head and capsid alternate attacks. Below 2/3 health, however, the boss will begin using attacks from both the head and capsid simultaneously.

Aftermath
Once the Esophage has been defeated for the first time, the following will occur:
 * The will begin selling.

Tips

 * The boss doesn't have to be fought at night or in the world evil biome, and fighting it during the day makes the attacks far easier to see coming.
 * The ichor spray can be dodged effectively by moving close to and above the boss, waiting for the attack to complete, then moving to the other side before the projectiles fall back down.
 * The fake capsid plates can be distinguished from the real ones before the ring forms, meaning one can figure out a safe direction to escape in more quickly.
 * Going underneath the boss is risky, as the legs move somewhat erratically and can deal unwanted hits (though their damage is significantly lower than that of the other attacks). Additionally, getting trapped underneath the flesh chunks attack makes it very difficult to avoid the teeth.