The spiderdemon, called the spider mastermind in The Ultimate Doom, Doom II, Final Doom and the Depths of Doom Trilogy's manual, is the boss of the final episode of Doom, Inferno, and again of the final episode of The Ultimate Doom, Thy Flesh Consumed. The PlayStation version of Doom in turn features two spiderdemons as the bosses of its final level, Redemption Denied on higher skill levels. The spiderdemon has 3000 hit points and is one of the toughest creatures in the game. The spiderdemon appears as a huge brain with facial features on it, mounted atop a cybernetic chassis with four mechanical legs and a super chaingun, making it similar to a spider at first glance.
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.
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.
A spiderdemon emits a demonic roar which starts low-pitched but progressively "grows" in a crescendo to a high-pitched tone once activated. The huge 'super 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 425 shots per minute. When a spiderdemon begins firing, it will not stop until its target moves out of view or dies, or if it is stunned (where it will walk a bit immediately after the pain state) or killed. Similar behavior can be observed in the heavy weapon dude and the arachnotron.
When killed, the spiderdemon's mechanical body shuts down (in a forcible way) and collapses. A soft, whirring-down sound is heard (similarly to the mechanical rotor of an electric drill stopping spinning) as the body falls 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 exploding sound, possibly from the collapsing brains) and all that remains are its shattered robotic legs and dismembered facial features in a huge pool of blood.
On hard skill levels, there will be a few barons with her. You can use them to weaken/kill the spiderdemon. Near the spiderdemon is a hidden area with a BFG9000 and some ammo. Check the walls while she is in a fight with an enemy so you do not risk being killed.
When fighting a spiderdemon, it is essential to keep one's distance as much as possible; even at medium range, the monster's attack can be devastating. 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 extremely dangerous, except in 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.
- Sprites for the spiderdemon were based on a model built under contract by Gregor Punchatz's company, TXFX. The model was the first of several models; subsequent ones were used for the monsters in Doom II. Punchatz designed the model based on a pencil sketch by Kevin Cloud .
- The appearance of the spiderdemon resembles the leader-brain from the 1986 version of Invaders from Mars.
- In the original Doom game, this monster is called just "spiderdemon". However, in Doom II cast sequence it has the less generic name "the spider mastermind".
- Despite being the final boss, several attributes of the spiderdemon are inferior to the cyberdemon, such as hit points, speed or pain chance. Since the two monsters have different types of weapons, there is no objective way to tell which one is more powerful.
- While the spiderdemon is considered more eminent in the original Doom game, the cyberdemon is given higher billing as the greater monster in Doom II. The spiderdemon is the last boss in Doom as well as in The Ultimate Doom's extra episode, Thy Flesh Consumed, and is credited with controlling the invasion of the Phobos and Deimos bases. However, in Doom II, the cyberdemon is the last monster fought in MAP29 before the actual final boss fight in MAP30, in addition to the spider mastermind appearing before the cyberdemon in the endgame cast sequence.
- The spiderdemon is one of the three enemies whose machine gun sounds like a shotgun being fired rapidly, along with the heavy weapon dude and the Wolfenstein SS. This originates from the fact that the spiderdemon and the shotgun guy share the same code for their attacks: the spiderdemon's "super-chaingun" fires three bullets with every shot, each having equal traits with the shotgun guy's shotgun attack. The traits were recycled for the single code used for both the heavy weapon dude and the Wolfenstein SS in Doom II.
- In the PlayStation, Sega Saturn and Game Boy Advance versions, the gunfire noise of the heavy weapon dude and the spiderdemon is changed to sound the same as the players' chaingun.
- Upon death the spiderdemon collapses into a heap, with an accompanying series of explosions. As she collapses, frame-by-frame analysis shows that a piece of metal from her cybernetic portion pierces her forehead from within as she dies. Her mouth, complete with pointed teeth still intact, is visible on her otherwise ruined corpse. Some have even speculated that the spiderdemon flips the player off during the death sequence, though that was most likely an accident on creating the graphics.
- The spiderdemon, along with the demon, revenant, mancubus, and cyberdemon are the only monsters whose dying sound clips includes noise other than the monsters' vocals; in this case, there are two loud explosions.
- The spiderdemon, arachnotron, and cyberdemon are the only monsters that constantly make sound when they walk.
- Near the beginning of Doom II MAP20, Gotcha!, the player is given the opportunity to lure the spiderdemon and the cyberdemon into fighting each other via monster infighting. Unless a third party intervenes, the cyberdemon usually wins in that map.
- The term 'spiderdemon' is actually a misnomer; Despite being called a "spider" the monster has only six visible limbs: two arms and four mechanical legs. Incidentally, the Doom novels inconsistently describe four mechanical legs at one point and six mechanical legs at another, though the novels themselves contain several continuity errors.
- The sprites are different from the original latex and metal model, as seen here. The model has a 3-barreled chaingun implanted right below the mouth, while the game sprites have a 6-barreled chaingun implanted into the base. It may not be a coincidence that the spiderdemon fires three bullets each time.
- The spiderdemon was originally intended to have a secondary "magic" attack. However, it was never implemented because the designers could not decide on what the attack would do.
- MAP28: The Spirit World in Doom II is the only level designed by id Software that includes more than one spiderdemon at the same time. Two appear near a group of arachnotrons, on the "Hurt me Plenty", "Ultra-Violence", and "Nightmare!" skill levels.
- The spiderdemon is also one of the rarest monsters in the game, appearing in only a few select levels.
- The PlayStation and Saturn ports' version of the spiderdemon only contains one sound clip, used for both an alert sound and a dying sound.
- As with all hitscan attack monsters, it is possible for two spiderdemons to infight each other. The only instance where this can happen in the official commercial levels is MAP28 of Doom II. This also occurs in the PlayStation/Saturn ports' final level, Redemption Denied.
|Shots needed to kill1,2||Mean|| Standard
health, no armor)
health, security armor)
health, combat armor)
|Baron of Hell||117.61||17.02||100||159|
- 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.
- The target must be close enough to compensate for the weapon's recoil.
- Assumes that direct hits are possible, which does not occur in any stock map.
The IWADs contain the following numbers of spiderdemons per skill level:
|Monsters from Doom and Doom II|
| Doom: Baron of Hell | Cacodemon | Cyberdemon | Demon | Imp | Lost soul | Shotgun guy | Spectre | Spiderdemon | Zombieman|
Doom 2: Arachnotron | Arch-vile | Commander Keen | Heavy weapon dude | Hell knight | Mancubus | Pain elemental | Revenant | Wolfenstein SS | Final boss