Spider Mastermind

The Spider Mastermind (also called the Spiderdemon) is a huge cybernetic demon that appears in the DOOM video game series. It appears as the final boss in both the original DOOM and DOOM (2016) while appearing as a high-level demon in DOOM II.

Classic Series
The Spider Mastermind commands the forces of Hell in the first DOOM game, thus appears as the game's final boss. It appears as a large, fleshy mass resembling a brain, featuring a pair of red eyes and a fang-filled mouth. It is attached to a robotic platform that moves about on four rigid legs. Attached to the base is a chaingun.

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. Like the Cyberdemon, the Spiderdemon is immune to splash damage. It can only be harmed by direct hits, so it will take a greater number of rockets to finally defeat it.

DOOM (2016)
In DOOM (2016), the Spider Mastermind is created when the game's main antagonist, Dr. Olivia Pierce, is merged with the essence of an ancient and all-powerful demon. Its appearance is similar to that of the original Mastermind from the first DOOM, but is much more stylized and futuristic-looking. The large, brain-like mass that makes up its body is held in place by mechanical parts and has two small organic arms. Its legs are curved and far less rigid than the stapler legs of the original. At the base of the Mastermind's mechanical platform is a plasma repeater cannon that fires streams of Argent energy pulses. However, the Mastermind has other weapons at its disposal as well, such as bombs and laser beams.

The Spider Mastermind has a large health pool and has a number of attacks which can cause serious damage to the player. Such attacks include jumping near the player and a sweep at the player with its legs, firing plasma bolts from its underslung gun, and firing a sweeping laser from the body as well as other lasers at the sides forcing a player to jump and crouch to dodge them. It can saturate the area with spiked bombs, as well as call upon pillars that rise up from the arena. Occasionally it will electrify the floor, which forces the player to climb up on these pillars. Sometimes it will cause spikes to rise from the pillars which can damage the player and thus it's a good idea to take the opportunity to use the BFG, especially given it remains stationary. The Super Shotgun can be used to inflict damage when the BFG stuns the Spider Mastermind, which yields health and ammunition pickups.

The Spider Mastermind's face is the most noticeable weakpoint, as the exposed brain and machinery do not seem to take much damage. The rocket launcher's lock-on feature is especially good for maintaining constant damage output. It will also sometimes invert itself, putting the gun turret above its head, though it will not shoot a sweeping laser like this. When most of its health pool is drained, the Spider Mastermind will crawl on its remaining legs to support itself and will turn upside down on itself to shoot lasers. Upon defeating the Mastermind, the player will initiate a unique Glory Kill which involves opening the Spider Mastermind's mouth, shoving the BFG down its throat and firing the weapon, regardless of remaining ammunition, resulting in the Spider's enormous brain being blown to pieces, and receiving a massive hole through the entire middle.