Aggron (5e Creature)
From D&D Wiki
Large elemental, any alignment
Siege Monster. The aggron deals double damage to objects and structures.
Heavy Metal. The aggron has advantage on saving throws to resist being moved.
Heavy Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 32 (8d6 + 4) bludgeoning damage.
Rock Slide. Ranged Weapon Attack: +2 to hit, range 60/180 ft., one target. Hit: 13 (4d6 - 1) bludgeoning damage.
Metal Burst. When the aggron takes damage from a melee attack, it can force the attacker to make a DC 15 Dexterity saving throw. On a failed save, the creature takes damage equal to the damage of the triggering attack, or half as much on a successful save.
The aggron's body, unlike that of its pre-evolution, lairon, is made of almost pure metal, and the little bits of earth that remain in its body are small pieces crushed deep in its core, yet its enormous steel body has been absorbed into its elemental essence.