Magic Resistance.

The juggernaut has advantage on saving throws against spells and other magical effects.

Siege Monster.

The juggernaut deals double damage to objects and structures.

Actions

Slam.

Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 11 (1d10 + 6) bludgeoning damage, and if the target is a Large or smaller creature, it must succeed on a DC 18 Strength saving throw or have the prone condition.

Bonus Actions

Devastating Roll.

The juggernaut moves up to its speed. During this movement, the juggernaut can move through the spaces of creatures with the prone condition. When the juggernaut enters the space of a prone creature for the first time during this movement, the creature must make a DC 18 Dexterity saving throw, taking 55 (10d10) bludgeoning damage on a failed save or half as much damage on a successful one.

Granite Juggernaut