Spidy, known as "Kūmosu" (クーモス,"Kūmosu") in Japan, is a virus from Mega Man Battle Network 4. It pauses for a moment on its side of the field until it moves in a straight line towards its target. It then continues to chase the target in a straight line around the target's field until either the virus or the target is deleted. Higher level variants shoot out two webs on random panels that can trap the target if the target runs into them. The webs disappear after a duration of time.
Spidy is a green variant with orange legs and yellow eyes.
SpidyEX is a yellow variant with pink legs and green eyes.
Webby is a orange variant with purple legs and orange eyes.
WebbyEX is a blue variant with yellow legs and orange eyes.
Arachy is a purple variant with turquoise legs and light green eyes.
ArachyEX is a black variant with white legs and red eyes.