Metroid Database Bestiary

Shortly after arriving on board the B.S.L, Samus encounters her first major battle with a Core-X formation of parasites who had previously copied her Morph Ball ability and mimic the native Arachnus creature from SR388. Like the original fire-spewing enemy, the Arachnus-X has a heavy protective shell and is capable of curling itself into a ball in order to aggressively crush and roll over opponents with devastating effect. Although the burly Arachnus-X has large claws, it prefers to use its enhanced biological ability to spew a spread of incendiary substances to engulf its victims in flames.

Arachnus-X is vulnerable to both Normal Beam or Missile attacks from the front. (On route to the boss, Samus can acquire two additional Missile Tanks which are helpful.)

There is a ledge on both sides of the room. Begin pummeling Arachnus-X with missiles once the Core-X manifests into that form, and be prepared to quickly dodge incoming flame and energy attacks by jumping back onto the nearest ledge. Arachnus will then attempt to roll into the wall to try and dislodge Samus's grip, so jump over to the other side of the room before he hits the wall. Repeat this process of shooting, dodging, and jumping to the other side of the room until the Arachnus form is defeated. The Core-X will re-appear and can be destroyed through a stage of three single Missile attacks.

One of Arachnus-X’s energy attacks may have been inspired by Samus’s ability to launch a fully charged beam attack when she rolls down into Morph Ball form. This extra move was first featured in Metroid: Fusion gameplay and was reworked into her move-set in Metroid: Zero Mission.

Along with the wider inclusion of ledge grabbing mechanics for traversal, Fusion also features an extra move which allows Samus to fire fully charged beams when hanging from any ledge or platform. Although not frequently used or highlighted, this subtle move (not to be confused with aiming while on a ladder) allows Samus to shoot enemies around a surface without having to largely expose herself, and could be seen as the first demonstration of a gunplay “cover system” posture within the series.