"This is going to be a terrible night..."
The Twins are a Hardmode Mechanical Boss which is essentially a harder version of the Eye of Cthulhu. The Twins are two separate flying entities connected by a tendril, each with its own attack pattern and life count. Both must be killed in order to defeat the boss.
The Twins are summoned using the Mechanical Eye at night, and must be defeated before dawn, otherwise they despawn. If an Altar has been destroyed, they also have a chance of spawning on a random night if they have not been defeated yet. Their approach is signaled at dusk via the chat message, "This is going to be a terrible night..."
While The Twins are alive, music Boss 2 will play.
- Retinazer: has an orange-red iris and fires purple lasers. It will usually attempt to remain vertically above the player.
- Spazmatism: has a green iris and fires balls of Cursed Flame. It will usually attempt to remain horizontally in line with the player.
Both alternate between their signature attacks and a charging melee attack, much like the Eye of Cthulhu. Retinazer's charge attack is faster and covers a bit more distance than Spazmatism's charge attack.
Each eye has a second form. Retinazer transforms at 8000 HP while Spazmatism transforms at 9000 HP.
- Retinazer becomes a mechanical eye with a laser turret in its pupil. It fires more rapidly and with higher damage, and periodically fires in quick barrages, but doing significantly less damage. The barrages become more intense and frequent the more damage Retinazer takes, eventually occurring nonstop. In its second form, Retinazer will only shoot at the player(s) and no longer attempt to ram into them.
- Spazmatism becomes a mechanical mouth. It chases the player, charging with greater speed and range, and periodically spews streams of Cursed Flames from its mouth in a manner similar to the Flamethrower. The flames can inflict the Cursed Inferno debuff and deal high damage.
- In Expert mode, Retinazer's laser firing become faster and charges become farther as its health depletes. Spazmatism's fireballs inflict Cursed Inferno for a longer length of time; sixteen seconds instead of eight. Spazmatism will also charge faster in its second form.
|| Mecha Mayhem • "Do battle against the Twins, the Destroyer, and Skeletron Prime simultaneously and emerge victorious."
| Defeat all three Mechanical Bosses simultaneously in a single battle.
|| Ophthalmologist • "You have defeated The Twins!"
| Defeat The Twins for the first time.
- Similar to the Eye of Cthulhu, The Twins will not spawn if you log out after the message "This is going to be a terrible night...," is displayed.
- The Twins will not spawn after the message "This is going to be a terrible night..." if all players are underground
- On Console and Mobile versions, if The Twins are summoned with a Mechanical Eye on a night where The Twins naturally spawn, both pairs will appear and all four eyes will be connected. This does not happen on the Desktop version.
- Both eyes can drop their respective trophy when killed, regardless of which is killed first or last. It is possible to get both trophies in one battle.
- In its second form, Spazmatism's eye fire functions almost identically to the Flamethrower weapon, with similar range and damage but inflicting the Cursed Inferno debuff instead of On Fire!.
- The Twins are defeated when the last eye alive is killed. On multiplayer it is possible that only one of two eye despawns while all players are dead. The battle can still be completed for whole loot (excluding the missing eye's trophy) provided that someone respawns near the remaining eye before it disappears.
For more elaborate strategies on defeating The Twins, including Weapon and Arena recommendations, see Guide:The Twins strategies.
- Concentrate on killing Spazmatism completely first, as its cursed flames are difficult to avoid in its second form. Fighting them both in their second phases simultaneously makes the fight significantly more difficult.
- Both of the Twins are vulnerable to the Frostburn, Ichor, and Cursed Inferno debuffs. As such, a viable combination is Frost Armor, a Megashark (if The Destroyer has been defeated), and either Ichor Bullets or Cursed Bullets. The Twins will be inflicted with two debuffs simultaneously.
- In both of the Twins second form, using items like a Cross Necklace or having Titanium armor greatly helps take less damage by becoming invincible during most of their strong "Rapid Attacks"
- If the Twins are ever out-run, such as with the case of a long railroad, they will despawn regardless of the time of night.
- Housing the Nurse near the arena and setting the player's spawn point there, will allow the player to teleport (via Magic Mirror, Cell Phone, or Recall Potion) to the Nurse for quick healing and removing of debuffs.
- Because Souls of Sight are used mainly for making magic based items, this boss is less rewarding to players going for ranger or melee/warrior builds.
- Shadowflame Knives and Cursed Flame-based weapons are an excellent against The Twins, as neither of them are immune to the Shadowflame and Cursed Inferno debuffs.
- The Sharanga is an excellent weapon against The Twins if it is fired as the player runs away.
- Retinazer's name is a portmanteau of retina, a part of the eye, and laser. Spazmatism's name is a portmanteau of astigmatism, an eye disorder, and spasm, meaning to twitch uncontrollably.
- The Twins are the only Mechanical Boss with phases, and is also the only mechanical boss that seems to be partially made of flesh, possibly being biomechanical hybrid. Unlike the other two, they are vulnerable to more debuffs.
- They are the only boss with two trophies.
- When shown on the minimap, the Twins' icons are incorrect. Retinazer starts off as its intended icon, but once enraged, the icon switches to an unenraged Spazmatism. Spazmatism however on the minimap is originally shown as an enraged Retinazer, when enraged, the icon changes to the correct enraged Spazmatism.
- Although The Twins spawn off the screen, the tendril between them can spawn in the screen.
- The Twins are the only Boss with a minion designed after it, though some bosses have minions designed after parts of it, e.g. Duke Fishron.
- For changes that affect all the mechanical bosses, see Mechanical Bosses#History.
- Spazmatism increased health to 23000, decreased damage for both.
- Spazmatism now transforms at 9000HP and Retinazer now transforms at 8000HP, instead of at half HP.
- Now only drops 15-30 Hallowed Bars.
- One of the twins can no longer despawn as long as the other is still active.
- Now have a chance to spawn during hardmode with the message: "This is going to be a terrible night...".
- Will now drop 20-40 Souls of Sight, instead of 20-30.
- Health and damage reduced from 24000 and 50 to 20000 and 40 respectively.