Skeletron Prime

""

Skeletron Prime is a Hardmode mechanical boss which is essentially a more difficult version of Skeletron. It consists of a head and four limbs, but, similar to Skeletron, only the head needs to be defeated to defeat the boss.

Skeletron Prime can be summoned manually using a Mechanical Skull at night. It can also spawn naturally upon dusk with a chance of 10% once a Demon or Crimson Altar has been smashed, as long as it has not yet been defeated in the current world. If spawning this way, its arrival is announced by the status message: "" ( alternatively "You feel the air getting colder around you..."). If it is not defeated before dawn, it will behave like a Dungeon Guardian.

While Skeletron Prime is alive, music Boss 1 will play.

Attacks
Skeletron Prime has four limbs which are all immune to the Poisoned and On Fire! debuffs:
 * Prime Cannon fires bombs that do not destroy blocks, usually up into the air rather than directly at the player. It usually stays above the player.
 * Skeletron Prime's Prime Saw and Prime Vice both act similarly to The Twins when they are charging, but the Prime Laser acts similarly to Retinazer or the Wall of Flesh while shooting laser beams.
 * Prime Saw usually remains under the player, then swipes upwards or downwards.
 * Prime Vice will swipe around wildly, making occasional lunges at the player. It usually remains diagonal to the player.
 * Prime Laser shoots red death lasers similar to those of Retinazer and The Destroyer, and is always pointed at a player. It usually stays horizontal to the player.

Skeletron Prime will occasionally enter a "rage mode", in which its attacks become more aggressive:
 * Skeletron Prime's Head will grow spikes and start spinning towards the player slowly. Damage and defense are doubled to /  and, respectively.
 * Prime Cannon will aim at the player directly and fire rapidly.
 * Prime Saw will begin homing directly towards the player's location.
 * Prime Vice becomes more aggressive and frequently lunges towards the player.
 * Prime Laser will fire more frequently.

Skeletron Prime is generally much more mobile than its predecessor Skeletron, and will regularly move off-screen. Like Skeletron, if it is not beaten by dawn, it behaves much like a faster Dungeon Guardian, except it travels at a speed of 65 instead of 41 MPH. If defeated this way he'll drop items normally.

Tips

 * Standing on platforms far from blocks can mostly nullify the effects of the Prime Cannon, as its projectiles only detonate on blocks, while passing through platforms harmlessly.
 * Unhindered movement is crucial when Skeletron Prime's head starts spinning, as it deals double the regular damage. Wings greatly aid in moving vertically, and flattened terrain or a sky bridge are convenient for horizontal movement.
 * Although it is a little more time-consuming, focusing on the arms first is very rewarding. Once Skeletron Prime's head is no longer shielded by anything, the fight gets a lot easier.
 * Due to Skeletron Prime's overall high defense, inflicting it with is effective, as he is not immune to it. Note that most Ichor weapons comparatively lack in damage, though, so they should only be used periodically for inflicting the debuff. Most Ichor-based ranged ammo, however, are highly effective if one gets a weapon with high ROF such as the Megashark.
 * In fact, as the head is Immune to Cursed Inferno, but not Ichor, Crimson World Players might have more advantage over Corruption World Players

Trivia

 * Skeletron Prime will open and shut its mouth for the entire battle. This is a purely cosmetic effect.
 * It is the only mechanical boss whose name contains the pre-Hardmode boss's name. Furthermore, it is the only mechanical boss to share boss music with its pre-Hardmode variant. Additionally, him and Skeletron's name do not have the word "The", unlike the other two Mechanical Bosses and The Eye of Cthulhu.
 * Unlike Skeletron, Skeletron Prime's defense doubles when its head is spinning.
 * Skeletron Prime's head is immune to the Cursed Inferno, Penetrated, Celled, and Daybroken debuffs. Its arms, however, are not.

History
Skeletron Prime Grand Squeletron 机械骷髅王