Bospider

Bospider (ボスパイダー), known as Bosspider in the remake Mega Man Maverick Hunter X, is the giant spider boss at the end of the first part of the final stages in Mega Man X, Mega Man Maverick Hunter X, and Mega Man Xtreme. It was developed to be a large-scale Crusher that was once used to crush scrap metal before being roped into guarding Sigma's fortress, where it moves in a web-shaped rail. Although it was supposed to be an invincible defense mechanism, the shock when hitting the ground causes it to expose its weak point due to a design error.

Strategy
Bospider creates random paths down its four rails to crush X, so the player must stay on the move. Its method of navigation is similar to Japanese lot-drawing, or Amidakuji. It has strong defense, but a red core on its abdomen, its weak point, will be exposed when it hits the ground. Occasionally it will spawn four Petitpiders before moving though it will also do this in the middle of its path if the player is in the air. As its health drops, Bospider will move faster while in Maverick Hunter X, the delay between the moment the lasers appear and the moment Bosspider starts moving decreases (in Hard difficulty only).

In Mega Man X, its main weakness is Shotgun Ice (along with Magnet Mine in Mega Man Xtreme). It is however difficult to hit the boss in time to hit the core when it appears, as it is only exposed for a short time.

Petitpider
Petitpider (プチパイダー). is a small spider Mechaniloid produced by a device within the Bospider's body. This enemy deals contact damage and runs along the walls of the boss room. Petitpiders also appear in Rockman X DiVE, as well as a red variant which chases the players and explode in contact with them.

Damage Data Charts
Displays the amount of damage in units that Bospider will receive from each Special Weapon in Mega Man X.

Archie Comics
Bospider appeared in Worlds Unite as part of Sigma-2's army. It later fights Mega Man and Sonic alongside its Petitpiders, but they are destroyed.

Trivia

 * When Bosspider dies in Maverick Hunter X, it rolls over onto its back and tucks its legs to its body before exploding which is a common misconception of how spiders die in real life. In fact, spiders never roll onto their backs, but stay upright while their legs curl up.