The Arachnoid, also known as the Terror of Tarantia, is a boss in Going Commando fought in the Megacorp Games on Joba. It is an eight-legged Mecha-Spider with a chrome body and a large dark-blue abdomen which has a row of bright blue lights. It is very fast and agile, able to jump the entire distance of the cage. With the use of its front legs it can spawn nidbots or fire electricity at foes. Ratchet and Clank fought it only during the arena challenge "Arachnoid Battle", which is exclusively a cage match.
It is quite fast, thus care must be taken to keep it in your sights. Be wary of any lone roaming nidbots and be ready to dodge any incoming lightning strikes