The Twins




Type | |
---|---|
Environment | |
Max Life | 430006450082237 (total) |
Defense | 10 |
KB Resist | 100% |
Immune to | ![]() ![]() |
Coins | 12 GC30 GC |
---|
- Item (Quantity)Rate
Soul of Sight (25-40)
100%Hallowed Bar (15–30)
100%Horned God Boots(Old-gen console version)
Greater Healing Potion (5–15)
100%- 14.29%
Treasure Bag(Desktop, Console and Mobile versions)(The Twins)
Mechanical Wheel Piece(Desktop, Console and Mobile versions)
100%- 14.29%
Soul of Sight (25–40)
100%Hallowed Bar (20–35)
100%- 100%
Pair of Eyeballs(Desktop, Console and Mobile versions)
Twins Relic(Desktop, Console and Mobile versions)
Hurt | |
---|---|
Killed | |
Hurt (mechanical) |
"This is going to be a terrible night..."
The Twins are a Hardmode mechanical boss which is essentially a more difficult version of the Eye of Cthulhu. The Twins are two separate flying entities, Retinazer and Spazmatism, 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 can be summoned manually using a Mechanical Eye at night (7:30 PM to 4:30 AM). They also have a 1/10 (10%) chance to spawn naturally at dusk once a Demon or Crimson Altar has been destroyed, as long as they have not yet been defeated at least once in the current world. If spawning this way, their arrival is announced by the status message "This is going to be a terrible night...".
The Twins must be killed before dawn, otherwise they flee and despawn.
While The Twins are alive, the music Boss 2 will play. When Otherworldly music (Desktop, Console and Mobile versions) is enabled, the track Boss 2 (Otherworldly) will play instead.
Eyes
There are two eyes: Retinazer and Spazmatism. Retinazer is a laser-shooting eye with a red iris; Spazmatism is a similar-textured eye, though it has a green iris. It fires green Cursed Flames.






Type | |
---|---|
Environment | |
AI Type | Spazmatism AI |
Damage | 50/85/127 (contact) 5088132 (Cursed Flame) [1] |
Max Life | 23000/34500/43987 |
Defense | 10 |
KB Resist | 100% |
Immune to | ![]() ![]() |
Debuff | ![]() |
---|---|
Debuff tooltip | Losing life |
Chance | 68.75% [2] |
Duration | 2–3 seconds (Desktop, Console and Mobile versions) [2] 3–8 seconds (Old-gen console and 3DS versions)4–6 seconds [2]5–7.5 seconds [2] |
Coins | 12 GC30 GC |
---|
Hurt | |
---|---|
Killed | |
Entering second phase |






Type | |
---|---|
Environment | |
AI Type | Spazmatism AI |
Damage | 75127190 (contact) 60108162 (Eye Fire) [1] |
Max Life | 9200/2300013800/3450017594/43987 [1] |
Defense | 28 [1] |
KB Resist | 100% |
Immune to | ![]() ![]() |
Debuff | ![]() |
---|---|
Debuff tooltip | Losing life |
Chance | 68.75% [2] |
Duration | 2–3 seconds (Desktop, Console and Mobile versions) [2] 3–8 seconds (Old-gen console and 3DS versions)4–6 seconds [2]5–7.5 seconds [2] |
Hurt | |
---|---|
Killed | |
Charge |
Behavior
First phase
- The eyeball with the red iris, Retinazer, fires purple, high-velocity
Eye Lasers. It will usually attempt to remain diagonally above the player.
- The eyeball with the green iris, Spazmatism, fires medium velocity balls of
Cursed Flame, which have a 11/16 (68.75%) chance of inflicting the Cursed Inferno debuff for 2–3 / 4–6 seconds. It will usually attempt to remain horizontally in line with the player.
Both eyes alternate between their signature ranged attacks and charging attacks, much like the Eye of Cthulhu. Retinazer charges four times while traveling much greater distances than Spazmatism at the expense of longer periods in between charges, while Spazmatism charges ten times within quick, high-velocity bursts that cover shorter distances.
Second phase
When one of the eyes' health dips below 40%, it spins before transitioning into its second form, casting off its retina to reveal its true mechanical visage before beginning to attack the player after a few seconds. Retinazer transforms at 8,000 / 12,000 / 15,300 HP while Spazmatism transforms at 9,200 / 13,800 / 17,594 HP. During their second phase, the defense of each eye is also increased to 20.
- Retinazer becomes a mechanical eye with a laser cannon in its pupil and now only fires red
Death Lasers, ceasing its attempts to ram the player (or align with the player diagonally). It fires more rapidly and with higher damage, and periodically fires in quick barrages which does significantly less damage. The barrages become more intense and frequent the more damage Retinazer takes, eventually occurring non-stop.
- (Desktop, Console and Mobile versions) Retinazer will, however, align horizontally with the player when firing barrages, though not as tightly as first-phase Spazmatism does. When not barraging, Retinazer will usually align itself vertically with the player from above.
- Spazmatism becomes a mechanical mouth (similar to the Eye of Cthulhu's second phase) that continuously pursues the player. It alternates between charging at the player six times with increased speed and range, and spewing Eye Fire from its mouth in the form of a continuous stream of Cursed Flames while slowly approaching the player for approximately seven seconds, in a manner similar to the Flamethrower. The stream of Cursed Flames also has a 11/16 (68.75%) chance of inflicting the Cursed Inferno debuff for 2–3 / 4–6 seconds. Spazmatism no longer attempts to align itself horizontally with the player.
In Expert Mode(Desktop, Console and Mobile versions), Retinazer's laser-firing becomes faster and its charges cover more distance as its health depletes. Spazmatism's flames inflict Cursed Inferno for 2× / 2.5× the duration while also charging faster in its second form.
Notes
This content is transcluded from Mechanical bosses § Notes.
- When spawning naturally, a mechanical boss spawns exactly 81 in-game minutes (at 8:51 PM) after the status message has appeared. Being in a layer lower than the Surface at that moment, or, in singleplayer, exiting the world during that timespan, will prevent the boss from spawning naturally.
- With the 1/10 (10%) chance of spawning naturally at dusk, the resulting chance for each mechanical boss is initially 1/30 (3.33%). Once one of them has been defeated, the remaining two have a resulting 1/20 (5%) chance of spawning naturally, and after defeating the second one, the last one has the full chance of 1/10 (10%).
- An Eye of Cthulhu naturally spawning will take precedence over a mechanical boss naturally spawning.[4]
- A Lantern Night(Desktop, Console and Mobile versions) occurring will prevent a mechanical boss from naturally spawning. However, summoning a mechanical boss using one of the summon items will cancel out the Lantern Night, just like any other boss summon.
- In a Get fixed boi(Desktop, Console and Mobile versions) world, the player cannot summon the mechanical bosses separately, they have to summon the Mechdusa instead.
- It is possible to summon a mechanical boss in pre-Hardmode if the summoning item is brought in from another world. However, if the Wall of Flesh has not been defeated, Plantera's Bulbs will not start spawning.
- Both eyes can drop their respective trophy when killed, regardless of which is killed first. It is also possible for both trophies to drop in one battle.
- On the
Old-gen console version and Nintendo
version, if The Twins are summoned with a Mechanical Eye on a night when The Twins are also spawning naturally, both pairs will appear and all four eyes will appear connected.
Achievements









Tips
- Focus on defeating one eye completely first without inflicting too much damage on the other one. Battling The Twins while both are in their second form makes the battle much more difficult, especially in Expert Mode(Desktop, Console and Mobile versions).
- Spazmatism may be a better choice for defeating first, since its Cursed Flames are difficult to avoid without proper mobility equipment and buffs in its second phase. Retinazer is less deadly, as it cannot inflict debuffs and will not charge in its second phase, which helps the player get some distance if they are a ranger.
- The Twins are only immune to Confused and (Desktop, Console and Mobile versions) Poisoned, so using a weapon that inflicts a debuff may be useful during the fight.
- A good arena for this boss is simply a long, flat plane. With Lightning Boots (or better) and a ranged or magic weapon, the player can continually outrun The Twins' attacks while firing back at them.
- In its second phase, Retinazer can only attack the player if it has an unobstructed line of sight. Hiding in a box prevents it from dealing any damage.
- A Gravitation Potion can be an excellent method of keeping distance from the Twins, allowing them to be attacked freely.
Trivia
- Retinazer's name is a portmanteau of retina, a part of the eye, and laser. Spazmatism's name is a portmanteau of spasm, meaning to twitch uncontrollably, and astigmatism, an eye disorder.
- Spazmatism's second form has visible bolts along either side, whereas Retinazer's second form only has them along one side.
- The Twins seem to have complete heterochromia iridum (two different eye colors).
- In its second phase, Spazmatism's Eye Fire attack functions almost identically to the Flamethrower weapon ((Old-gen console and 3DS versions)), with similar range and damage, but inflicting the Cursed Inferno debuff instead of On Fire!.
- The Twins are the only boss with two trophies, and the only mechanical boss with more than one phase.
- Despite inflicting it, Spazmatism is not immune to Cursed Inferno.
- The Twins are one of three bosses with a corresponding minion (Optic Staff), the others being the Martian Saucer(Desktop, Console and Mobile versions) (Xeno Staff(Desktop, Console and Mobile versions)) and Duke Fishron (Tempest Staff).
– According to the Terraria lore pages, The Twins were one of the three mechanical recreations of Cthulhu's missing organs. They are a recreation of Cthulhu's eyes.
- The Twins seem to be bio-mechanical hybrids since they are not immune to debuffs like On Fire!, Cursed Inferno, (Old-gen console and 3DS versions) Poisoned, or Acid Venom, even when transformed.
Bestiary entries
- Retinazer: "Belonging to a pair of mechanically recreated Eyes of Cthulhu, this one focuses its energy into firing powerful lasers."
- Spazmatism: "Belonging to a pair of mechanically recreated Eyes of Cthulhu, this one chases at high speed, exhaling cursed flames."
See also
- The Destroyer
- Skeletron Prime
- Mechdusa
- Twins of Terror at the Don't Starve Wiki
History
- Desktop 1.4.1.2: Now immune to Poisoned.
- Desktop 1.4.0.1:
- The Twins now use their map icons correctly. Before this, Retinazer used all first phase icons while Spazmatism used all second phase icons.
- Decreased Spazmatism's Cursed Inferno duration to compensate for increased Cursed Inferno DPS. The debuff can now last for 3 / 6 / 7.5 seconds (chance of 6/16 (37.5%)), 2 / 4 / 5 seconds (5/16 (31.25%)), or not be inflicted at all (5/16 (31.25%)). Previous durations were 8 / 16 seconds (chance of 8/48 (16.67%)), 5 / 10 seconds (10/48 (20.83%)), 3 / 6 seconds (15/48 (31.25%)), or not being inflicted at all (15/48 (31.25%)).
- Added the Pair of Eyeballs and the Twins Relic as Master Mode drops.
- Desktop 1.3.5: Sprites updated.
- Desktop 1.3.0.1: Added the Mechanical Wheel Piece as an Expert Mode drop.
- Desktop 1.2.3:
- Increased Spazmatism's health to 23,000, decreased damage for both.
- The Twins now transform at 2/5th HP, instead of at half HP.
- Now only drop 15–30 Hallowed Bars instead of 20–35.
- One of The Twins can no longer despawn as long as the other is still active.
- Desktop 1.2:
- Now have a chance to spawn naturally at dusk 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 for both reduced from 24,000 and 50 to 20,000 and 40, respectively.
- Desktop 1.1: Introduced.
- Console 1.0.933.1: Added the Mechanical Wheel Piece as an Expert Mode drop. (
)
- Console 1.0.750.0: Added the Mechanical Wheel Piece as an Expert Mode drop. (
)
- Console 1.06:
- Increased Spazmatism's health to 23,000, decreased damage for both.
- The Twins now transform at 2/5th HP, instead of at half HP.
- Now only drop 15–30 Hallowed Bars instead of 20–35.
- One of The Twins can no longer despawn as long as the other is still active.
- Console 1.02:
- Now have a chance to spawn naturally at dusk.
- Will now drop 20–40 Souls of Sight instead of 20–30.
- Health and damage for both reduced from 24,000 and 50 to 20,000 and 40, respectively.
- Console-Release: Introduced.
- Switch 1.0.711.6: Introduced with changes up to Desktop 1.3.0.1.
- Mobile 1.2.11212:
- Increased Spazmatism's health to 23,000, decreased damage for both.
- The Twins now transform at 2/5th HP, instead of at half HP.
- Now only drop 15-30 Hallowed Bars instead of 20–35.
- One of The Twins can no longer despawn as long as the other is still active.
- Mobile 1.2.6508:
- Now have a chance to spawn naturally at dusk.
- Will now drop 20–40 Souls of Sight instead of 20–30.
- Health and damage for both reduced from 24,000 and 50 to 20,000 and 40, respectively.
- Mobile 1.1.5536: Introduced.
- 3DS-Release: Introduced with changes up to Desktop 1.2.
References
- ↑ 1.0 1.1 1.2 1.3 Information taken from the
Desktop 1.4.0.5 source code, method
AI()
inTerraria.NPC.cs
. The relevant part is theaiStyle == 31
block. There may be inaccuracies, as the currentDesktop version is 1.4.4.9.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Information taken from the
Desktop 1.4.0.5 source code, method
StatusPlayer()
inTerraria.Projectile.cs
. The relevant part is thetype == 96 || type == 101
block. There may be inaccuracies, as the currentDesktop version is 1.4.4.9.
- ↑ 3.0 3.1 3.2 3.3 Information taken from the
Desktop 1.4.0.5 source code, method
AI()
inTerraria.NPC.cs
. The relevant part is theaiStyle == 30
block. There may be inaccuracies, as the currentDesktop version is 1.4.4.9.
- ↑ Information taken from the
Desktop 1.4.3.6 source code, method
UpdateTime()
inTerraria.Main.cs
. There may be inaccuracies, as the currentDesktop version is 1.4.4.9.
- Pages with non-numeric formatnum arguments
- Desktop content
- Console content
- Old-gen console content
- Mobile content
- 3DS content
- Surface NPCs
- Night NPCs
- Space NPCs
- Boss NPCs
- Hardmode-only NPCs
- Retinazer AI NPCs
- Pages with information based on outdated versions of Terraria's source code
- Spazmatism AI NPCs
- Achievement-related elements
- DST crossover content