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"You guess the Arachnotrons had to come from somewhere. Hi, Mom. She doesn't have a plasma gun, so thank heaven for small favors. Instead, she has a super-chaingun. Crap!"
Doom II instruction manual
Meet spider

The Spiderdemon is king of the hill in Doom, on E3M8: Dis.

The Spiderdemon (also known as the Spider Mastermind, as named in The Ultimate Doom, Doom II, Final Doom and the Depths of Doom Trilogy's manual) is the final boss of the first Doom, and in the final episode of The Ultimate Doom, Thy Flesh Consumed. The Spiderdemon makes its return as a normal enemy in the second game, where it first awaits in MAP06 (if the difficulty setting is chosen in Ultra-Violence or Nightmare) to seek vengeance against the player.

Physical Appearance[]

The Spiderdemon appears as a huge brain with facial features of menacing teeth and eyes that blink yellow when attacking. It is mounted atop a cybernetic chassis with four mechanical legs and a chaingun, making it similar to a spider at first glance.

Combat Characteristics[]

A Spiderdemon emits a loud demonic roar mixed with whirring machinery, starting low-pitched but progressively growing into a crescendo, high-pitched tone once activated. This roar is loud enough to be heard from a distance, no matter how far the player is. The Spiderdemon has audible footsteps, sounding similar to a running machinery.

The Spiderdemon relies on firing it's huge chaingun from its chassis. It fires three bullets with every shot, much like the Shotgun Guy's shotgun, but at a rapid rate of 467 shots per minute. When a Spiderdemon begins firing, it will not stop until its target is destroyed, moves out of view, or if the monster itself is stunned (where it will walk a bit immediately after the pain state) or killed. Similar behavior can be observed in the Wolfenstein SS, Heavy Weapon Dude and the Arachnotron.

Spiderdemons, like Cyberdemons, are immune to all blast damage, taking only direct hit damage from hits. This means a greater number of rockets are required to kill them than might be expected.

When killed, the Spiderdemon's mechanical body shuts down (in a forcible way) and collapses. A soft, whirring-down sound (similar to a mechanical rotor cooling down and stopping spinning) is heard as the body falls sideways to the ground, engulfed in flames. Its brain is splattered on impact (similarly to the Cyberdemon), the monster then emits an animalistic grunt that is readily cut out by an explosion, and all that remains are its shattered robotic legs and dismembered facial features in a huge pool of blood.

Tactical Analysis[]

General tactics[]

When fighting a Spiderdemon, it is essential to keep one's distance as much as possible and to keep whatever cover exists between you and it; even at medium and long range, the monster's super chaingun attack is devastating, and since the attack is hitscan, it cannot be evaded like the projectile attacks of other demons. Using the more powerful weapons is recommended against it, although since the Spiderdemon has a low pain chance, rapid-fire weapons will not completely prevent it from attacking. Using melee attacks against it is almost always an exercise in suicide, as the bullets will push the player backwards, rendering them unable to make contact with the Spider Mastermind. The exception is the rare cases where the Spiderdemon is pinned by another attacker. In E3M8: Dis, it is possible to stand up on the ledge above ground level and stay at great distance from the monster. At this range, the Spiderdemon's attack will not aim toward the player, and therefore never hit its target. Also, the Spiderdemon is large and tall enough that, even while standing on the ledge, projectile attacks will reach it.

However, due to its large size, it will soak in most if not all BFG rays from a point blank shot, dying in only 1 or 2 hits. A skilled player can therefore kill it easily by running up to it and shooting it twice with the BFG before it can kill the player. Utilizing monster infighting can be effective when battling a Spiderdemon. If one does not have the BFG, the rocket launcher or the plasma gun are recommended.

Though it has inferior hitpoints and lacks the sheer explosive power from its weapon like the Cyberdemon, the Spiderdemon still has easy dominance in monster-to-monster fights due to the high damage and wide hitscan from it's chaingun attacks. It is able to calmly mow down even powerful non-boss monsters such as a Mancubus or Baron of Hell, provided the Spiderdemon sustains fire until victory. This monster can sometimes even handle it's own against an individual Cyberdemon (seen in MAP20), with a random and fairly balanced chance of victory due to the Spiderdemon's reduce pain chance (except under the player's interference). Like all hitscan-based enemies, the Spiderdemon will gladly turn against their own species if caught in the crossfire.

Saturn version[]

Because the Spiderdemon suffers from slowdown to a greater extent than the player character's weapons in the Saturn version, it takes a split second longer to recover from pain, making it possible to completely prevent a Spiderdemon from attacking by shooting it with the chaingun.


ID # Hit points Speed Width Height Reaction time Pain chance Pain time Mass Bits
7 (decimal)
7 (hex)
3000 12 map units per frame
(140.0 map units per second)
256 100 8 40 (15.63%) 6 tics 1000 4194310

1: 2: 22:
Obstacle Shootable Affects Kill %

Sprite name Alert sound Chase sound Action sound Pain sound Death sound


Type Damage Shots per minute Sprite Sound
Hitscan 3-15 (per pellet)
9-45 (total)
466.7 PUFF (impact, miss)
BLUD (impact, hit)


Damage done by each shot from the super-chaingun

Shots needed to kill1 Mean Standard
Min Max
Player (100%
health, no armor)
12.29 2.16 9 19
Player (100%
health, security armor)
17.86 2.79 13 26
Player (200%
health, combat armor)
44.18 6.03 37 59
Barrel 2.93 0.83 2 6
Trooper 2.93 0.83 2 6
Sergeant 3.91 1.04 2 7
Wolfenstein SS 6.37 1.39 4 11
Imp 7.43 1.53 5 13
Chaingunner 8.80 1.74 5 15
Lost Soul 12.29 2.16 9 19
Commander Keen 12.29 2.16 9 19
Demon 17.86 2.79 13 26
Spectre 17.86 2.79 13 26
Boss Brain3 29.78 4.39 25 42
Revenant 35.44 5.22 30 50
Cacodemon 47.41 6.88 40 64
Pain Elemental 47.41 6.88 40 64
Hell Knight 58.95 8.61 50 82
Arachnotron 58.95 8.61 50 82
Mancubus 70.57 10.22 60 96
Arch-vile 82.52 12.01 70 114
Baron of Hell 117.61 17.02 100 159
Spiderdemon 351.57 51.06 303 473
Cyberdemon 468.91 68.19 405 631
  1. This table assumes that all calls to P_Random for damage, pain chance, blood splats, and bullet dispersal are consecutive. In real play, this is never the case: counterattacks and AI pathfinding must be handled, and of course the map may contain additional moving monsters and other randomized phenomena (such as flickering lights). Any resulting errors are probably toward the single-shot average, as they introduce noise into the correlation between the indices of "consecutive" calls.
  2. The target must be close enough to compensate for the weapon's recoil.
  3. Assumes that direct hits are possible, which does not occur in any stock map.

Appearance Statistics[]

In classic Doom, the Spiderdemon is first encountered on these maps:

Ultimate Doom E3M8: Dis E3M8: Dis E3M8: Dis
Doom II MAP20: Gotcha! MAP20: Gotcha! MAP06: The Crusher
TNT: Evilution MAP20: Central Processing1 MAP20: Central Processing MAP14: Steel Works
Plutonia MAP05: Ghost Town MAP05: Ghost Town MAP05: Ghost Town

The IWADs contain the following numbers of Spiderdemons:

Ultimate Doom 2 2 2
Doom II 2 4 5
TNT: Evilution 2 1 3
Plutonia 3 4 4
  1. May be encountered earlier if the super secret level is played.