Unused NPCs

Within Terraria there are several NPCs that are unused for one reason or another.

Unspawnable NPCs
These NPCs are functional, but do not appear at any time during regular gameplay. They can only only be spawned in by use of a mod or with third-party server commands.

Unused NPCs
These NPCs are incomplete, and cannot be spawned even with the use of mods. Various files or ID names may be present in code.

Unused projectiles
These projectiles exist in Terraria's files, but cannot be spawned even with the use of mods. Various files or ID names may be present in code. {| class="terraria" !Name !Sprite !ID !Notes
 * Mud Ball
 * [[File:Mud Ball.png]]
 * 39
 * Looks like recolored Dirt Ball.
 * Ash Ball
 * [[File:Ash Ball.png]]
 * 40
 * Looks like recolored Dirt Ball.
 * Frost Blast
 * [[File:Ice Bolt.png]]
 * 128
 * Has sprite of Icewater Spit.
 * Rune Blast
 * [[File:Ice Bolt.png]]
 * 129
 * Has sprite of Icewater Spit.
 * Cannonball
 * [[File:Cannonball.png]]
 * 240
 * Duplicate of projectile 162.
 * Scutlix Crosshair
 * [[File:Lightning Orb Arc.png]]
 * 441
 * Very likely used for testing.
 * Drill crosshair
 * [[File:Lightning Orb Arc.png]]
 * 453
 * Very likely used to test Drill Mount.
 * [[File:Projectile_457.png]]
 * 457
 * Has same texture as Phasic Warp Ejector.
 * [[File:Projectile_458.png]]
 * 458
 * Possibly shot from Phasic Warp Ejector.
 * [[File:Projectile_505.png]]
 * 505
 * [[File:Projectile_506.png]]
 * 506
 * Looks like recolored Spiky Ball.
 * Energy
 * [[File:Lightning Orb Arc.png]]
 * 526
 * Starmark
 * [[File:Starmark.png]]
 * 540
 * Surpisingly, it's not pixelated, unlike other things in Terraria.
 * Poison Spit
 * [[File:Lightning Orb Arc.png]]
 * 572
 * Alien Goop
 * [[File:Lightning Orb Arc.png]]
 * 581
 * Laser Ray
 * [[File:Laser Ray (projectile) 2.png]]
 * 592
 * Similar to the image for Laser Rays fired by Ray Gunners, but is blue.
 * Prophecy's End
 * [[File:Prophecy's End.gif]]
 * 593
 * Blowup Smoke
 * [[File:Lightning Orb Arc.png]]
 * 594
 * Laser
 * [[File:Laser2 (projectile).png]]
 * 606
 * Blood Water
 * [[File:Blood Water.png]]
 * 621
 * Has the texture of Blood Water item.
 * Blowup Smoke
 * [[File:Lightning Orb Arc.png]]
 * 622
 * Duplicate of Projectile 594.
 * Released Energy
 * [[File:Lightning Orb Arc.png]]
 * 629
 * Prophecy's End
 * [[File:Prophecy's End.gif]]
 * 593
 * Blowup Smoke
 * [[File:Lightning Orb Arc.png]]
 * 594
 * Laser
 * [[File:Laser2 (projectile).png]]
 * 606
 * Blood Water
 * [[File:Blood Water.png]]
 * 621
 * Has the texture of Blood Water item.
 * Blowup Smoke
 * [[File:Lightning Orb Arc.png]]
 * 622
 * Duplicate of Projectile 594.
 * Released Energy
 * [[File:Lightning Orb Arc.png]]
 * 629
 * 622
 * Duplicate of Projectile 594.
 * Released Energy
 * [[File:Lightning Orb Arc.png]]
 * 629
 * 629