Sources
CR
Type
Size
Alignment
Movement

Stone Juggernaut

Large Construct, Unaligned

Armor Class 15 (natural armor)
Hit Points 157 (15d10 + 75)
Speed 50 ft.
STR
16
+3
DEX
12
+1
CON
15
+2
INT
14
+2
WIS
14
+2
CHA
16
+3
Damage Immunities poison; bludgeoning, piercing, slashing, from nonmagical attacks not made with adamantine weapons
Condition Immunities Blinded, Charmed, Deafened, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned, Prone
Senses blindsight 120 ft., passive Perception 10
Languages
Challenge 12 (8,400 XP)

Traits

Devastating Roll. The juggernaut can move through the space of a prone creature. A creature whose space the juggernaut enters for the first time on a turn must make a DC 17 Dexterity saving throw, taking 55 (10d10) bludgeoning damage on a failed save, or half as much damage on a successful one.

Immutable Form. The juggernaut is immune to any spell or effect that would alter its form.

Regeneration. As long as it has 1 hit point left, the juggernaut magically regains all its hit points daily at dawn. The juggernaut is destroyed and doesn't regenerate if it drops to 0 hit points.

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:25 (3d12 + 6) bludgeoning damage. If the target is a Large or smaller creature, it must succeed on a DC 17 Strength saving throw or be knocked prone.

Lore

A stone juggernaut is a rolling construct imbued with enough awareness to avoid obvious dangers such as open pits and chasms. It trundles across open battlefields or rolls down dungeon corridors, crushing anyone in its path. Every stone juggernaut has a unique shape and appearance. One might resemble an elephant with bejeweled tusks, while another might look like a scowling demon with flaming eyes and obsidian teeth.