The Spider 'Mech is a gigantic spider-like machine, throughout the entire game it is only encountered once. It is fought for one of the datacores. Apparently it is not a brand new model but a very old one possibly made to keep the datacore safe. It also has a relative made by the Word of Blake which is a smaller version of it - the Mini-Spider. These things don't have the stomp attack and don't posses the shielding on the normal Spider. Their attack capabilities are also very limited, and do not pose a serious threat unless in swarms.