The Spider Boss [referred as "サソリ型機動兵器 (Scorpion-shaped mobile weapon)" in Japanese] is a colossal boss robot that appears in Stage 3 of Razing Storm. It surprised the S.C.A.R alpha members after they have completed the mission of delivering the coordinates of Paulo Guerra's base of operations to bravo team and clearing some enemies.
It has six legs which allows fast movement, two claws to grasp objects and fling them, and two laser irradiator "segments", an even more powerful main laser cannon which also has the ability to produce lethal bubbles, and missile launchers.
It's weakpoint are the laser cannons. However, it has the ability to repair itself even after taking plenty of damage such as destroying the laser cannons. Even after receiving damage from the satellite laser cannon, it recharges for the last time, firing plenty of missiles that the player must destroy before the link bridge they are on is destroyed by the missiles.
- It resembles NANCY-MI847J from Tekken 6.