Kataphron Battle Servitors
Kataphron Battle Servitors are Combat Servitors given an upgrade. They act as elite shock troops meant for dealing with heavier and tougher opponents that their smaller cousins couldn't do. Due to the opponents they face, Kataphron Battle Servitors are far, far larger and heavier, requiring anti-tank weapons take them down and even that doesn't work all the time.
Their increased size due to the heavier armor has rendered their already augmented human legs as too impractical and more vulnerable to wear and tear, instead opting for giant tank threads. While this may severely reduce its agility, speed and overall flexibility, the threads do enable more stability, durability and adaptability that normal human legs couldn't survive even when augmented.
Completely severed from all emotion and independent thought, these machines are little more than a living weapon controlled by Tech Priests. There are two types of Kataphrons which the Mechanicus uses.
Kataphron Breachers
Kataphron Breachers are used by the Mechanicum as a living shield and battering ram, smashing apart enemy lines and formations. They are quite deadly in close quarters combat, equipped with a large array of weapons that can include Arc Rifles, Torsion Cannons, Arc Claws, Hydraulic Claws, and Plasma Calivers. These machines are also equipped with a Kataphron Breacherplate, powerful cybernetically-enhanced titanium-laced metal and plastisteel that turns aside blades and bullets alike.
In terms of tabletop rules. The Kataphron boasts a MEQ-equivalent armor save, an Arc Rifle with the Haywire rule, and a CCW that also has Haywire. It can alternately switch that CCW for a different one that lets it exchange all its attacks for a single S10 AP1 hit (which you will always take since it'll only be attacking once either way) or replace its gun for a Torsion Cannon- a S8 AP1 weapon that causes unsaved wounds/penetrating hits to remove D3 wounds/HP instead of the usual 1. As it names implies, Breachers mutilate fortifications and even tanks with relative ease.
Kataphron Destroyers
You want to fuck up that column of Terminators and Battlesuits, you want to wipe the smile off that grinning Ultrasmurf Fanboy and Weeaboo Faggot. You need the Kataphron Destroyers. Kataphron Destroyers are used as heavy weapon platforms by the Mechanicum, ensuring that nothing will be left of their enemies but molten sludge. Thus they are equipped with a large amount of heavy weaponry that includes Grav Cannons, Phosphor Blasters, Plasma Culverins, and Flamers to completely eviscerate enemy armor. For protection, these machines are equipped with Kataphron Demiplates, lighter armour that allows better cooling of its heavy weaponry. Nonetheless this cybnernetically enhanced heavy steel provides a great deal of protection.
On tabletop, Kataphron Destroyers by default start with a Plasma Culverin and a cover-reducing Phosphor Blaster, but you're better off switching them for the Heavy Grav-Cannon and Cognis Flamer. The former will tear apart armor, and the latter always scores three hits in overwatch, which will ensure nobody with a brain will want to charge it.