Before the warforged were perfected, House Cannith developed the warforged titan for use in the Last War. Unlike their latter-day brothers, these massive war golems are essentially mindless, and lack the souls found in warforged. Most warforged titans were created in creation forges in the now-destroyed nation of Cyre, and fought for that nation in the Last War. As heavily armored war machines, the juggernauts are among the best at dealing damage and sustaining punishment. The Juggernaut was treated as a prestige class in both 3.5e and 4e.
Powerfully built with adamantine plates around their bodies, warforged juggernauts look bigger and tougher than their counterparts. Juggernauts grow armor spikes and are able to use them as weapons. As they embrace their construct heritage, they abandon the weaknesses of their living aspects, becoming even more resistant to damage and immune to mind effects.
Warforged in general already face a society that sees them as symbols of a war no one won but hurted everyone. Juggernauts are even more distant than regular warforged and that’s why they’re seen as war machines. In the Eberron campaign setting, it wouldn’t be rare seeing them as part of the Lord of Blades’ army, proclaiming they should be ruling the world.
In your campaign
A juggernaut is a weapon of destruction and siege. Use it to destroy defending locations with bull rush, charging and breaking down doors or even walls. Keep in mind that as juggernaut are more like constructs than living ones, they may be as well immune to healing effects.