Web Spider attacks X or Zero by dropping down from off-screen and firing a Lightning Web at them. The Lightning Web has slight homing capability, and it will immobilize them and drain their life if it catches them. After firing his web, Web Spider will then go back into hiding and repeat this pattern. Whenever he fires a Lightning Web, he shouts something indiscernible-- some believe that he says "try it!", though this has not been verified.
After his health bar is reduced to about one third, Web Spider will drop to the center of the screen and generate a large web that he moves around on in a somewhat unpredictable fashion. He will occasionally stop to release four small spider drones that move around the room, or fire a Lightning Web at X or Zero.
When X defeats Web Spider, he receives the Lightning Web. X can fire the web a fixed distance in front of him, and it will stay in the air for a few seconds before it disappears. The Lightning Web can actually be used as a temporary wall, as X can wall jump off of it to reach otherwise inaccessible locations.
When Zero defeats Web Spider, he receives the Raijingeki. Raijingeki is a saber technique that is executed by pressing the special weapon button while standing on the ground, and allows Zero to charge his saber with electricity and perform a forward lance-like attack. While the attack has a recovery time that can leave Zero vulnerable, it is quite powerful and it can combo with the first two slashes of his standard Z-saber combo.