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 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.

The Doom II game booklet humorously 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." It has since been confirmed that this comment is comic relief, and the genderless Spider Mastermind is not actually the biological mother of the Arachnotrons (this is evident in later levels where both monsters can be tricked by infighting).

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 Nazi Soldier, 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.

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)
Player (100%
health, security armor)
Player (200%
health, combat armor)
Wolfenstein SS6.371.39411
Lost soul12.292.16919
Commander Keen12.292.16919
Boss brain329.784.392542
Pain elemental47.416.884064
Hell knight58.958.615082
Baron of Hell117.6117.02100159
  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 DoomE3M8: DisE3M8: DisE3M8: Dis
Doom IIMAP20: Gotcha!MAP20: Gotcha!MAP06: The Crusher
TNT: EvilutionMAP20: Central Processing1MAP20: Central ProcessingMAP14: Steel Works
PlutoniaMAP05: Ghost TownMAP05: Ghost TownMAP05: Ghost Town

The IWADs contain the following numbers of Spiderdemons:

Ultimate Doom222
Doom II245
TNT: Evilution213
  1. May be encountered earlier if the super secret level is played.
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