The Spider Tank is a hexapedal walker. Following the general Union design aesthetic, it has an intimidating insect-like appearance, reminiscent to that of spiders or scorpions. They are about twice as large as the Striders used by the Polity. They are however, in some ways more mobile/manoeuvrable than Striders.
Spider Tanks have excellent all-terrain locomotion, being capable of scaling buildings, mountainsides and even tall structures such as Behemoth legs. While they typically move at a sedate walking pace, they also come equipped with foot-mounted rollers that allow them to travel at high speed along flat surfaces, most notably roads.
- Main cannon in the top-mounted turret
- Hull-mounted cannon
- Six quintuple missile pods beneath the main turret
- Two "claw"-mounted heavy machine guns
- Web Shooters (for both obstacle crossing and capturing/holding enemy units)
- Physical attack capability with its frontal legs to kick a target
However, their arsenal, while powerful, has some disadvantages. Most of their armament seems to be concentrated in frontal part of the hull, without the ability to traverse much.
The armor of a Spider Tank is capable of withstanding fire from Strider autocannons and Holon rifles at approximately 200 meters, but heavier weaponry, such as tank cannons or missiles, can quickly overwhelm them. Kazu's Holon sword also slices through these mechs with relative ease.
- Before the official name was confirmed, fans of the show referred to the Spider Tank as the 'Union Mech'.