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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 appears again in the final episode of The Ultimate Doom, Thy Flesh Consumed. The PlayStation and Saturn versions of Doom in turn feature two Spiderdemons as the bosses of its final level, Redemption Denied on harder skill levels. The Spiderdemon has 3000 hit points and is one of the toughest creatures in the game.


As described in the Official Doom FAQ without gender; It is a 'huge robotic chaingun shooting spider', it will make you wish you never were playing DOOM in the first place. Watch for it at the end of the third episode of DOOM, and numerous times times in DOOM II.

Spider Masterminds have been described with both male and female gender.

Can this crawling aberration be the brains behind the mayhem? It makes you wonder. Was the discovery of the Anomalies purely accidental? Or are there darker machinations here at play? Perhaps you can't answer these questions now. And answering questions will be the last thing you'll want to do when you confront the Spider Mastermind. Equipped with an ultra-speed machine gun, this cyber-organic miscreation is truly unstoppable. You'll need to enlist the aid of those you've been trying to annihilate all along. This is a situation you might actually be happy to see a horde of Cacodemons and the dreaded Cyberdemon.[1]

The Doom II game booklet presents the Spiderdemon as the mother of the Arachnotrons: "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." The stronger mutated Arachnotrons of Doom 64 are described as being like black widows.

The Doom II Official Strategy guide has this to say about the creatures which are the fathers of the Arachnotrons: "Daddy longlegs doesn't show often in DOOM II, and when he does you often have some alternate methods of killing him. The boss spider has a chaingun enbedded in his face, but he has to spot and acquire you before he can fire. Fortunately, he often seems preoccupied with other matters, and is not the best at tracking a fast-moving target. Once you learn to control fluid fire and movement, this guy's is actually a lot easier to polish off than the Cyberdemons. It takes 150 plasma hits, 15 rockets, or three BFG 9000 blasts to unravel this guy's evil web.

It further goes onto say that Arachnotrons are offspring of the Spiderdemon that was the final boss in the original Doom. They are nastier offensively, slinging green plasma bolts like pissed off Barons of Hell. But they can't stand the same level of damage as their daddy before going legs up.[​1]​

Don't even think of taking on Mr. Spider Mastermind alone unless you have a full supply of cells and rockets and all the health and armor you can stand.[2]

The Spiderdemon is not mentioned in the Doom game booklet, presumably to avoid a spoiler. Perhaps as a result of this, the game booklet for the Depths of Doom Trilogy erroneously states that it appears in Doom II only.

Physical Appearance

The Spiderdemon appears as a huge brain with facial features of menacing eyes and teeth, 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 demonic roar mixed with loud, whirring machinery which starts low-pitched but progressively "grows" in a crescendo to a high-pitched tone once activated. The huge chaingun on the Spiderdemon's chassis 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 moves out of view or dies, or 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 sidewards to the ground, engulfed in flames. Its brain is splattered on impact (at this moment, 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 not having the sheer explosive power of a Cyberdemon's rockets, the Spiderdemon still has easy dominance in monster-to-monster fights due to the firing speed and damage of its chaingun bullets, being 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 proves true even when pitted against the Cyberdemon - as seen in MAP20 from Doom II, where the two bosses can clash against each other - with random and fairly balanced chance of victory for both sides due to the Spiderdemon's reduce pain chance (except under the player's interference).

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.
  1. Doom Survivor's Guide, pg 27
  2. Doom Suvvivor's Guide, pg 27