Warden

Keen Hearing and Smell. The warden has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Magic Weapons. The warden's weapon attacks are magical.

Magic Resistance. The warden has advantage on saving throws against spells and other magical effects.

Relentless. If the warden takes 30 damage or less that would reduce it to 0 hit points, it is reduced to 1 hit point instead.

Shambler. When it doesn't detect any creatures nearby, the warden's speed is halved.

Avoidance. If the warden is subjected to an effect that allows it to make a saving throw to only take half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Burrower. The warden can burrow through dirt, solid stone, and sculk without disturbing the material.

Destroyer. The warden deals quadruple damage to objects and structures.

Freedom of Movement. The warden ignores difficult terrain, and magical effects can't reduce its speed or cause it to be restrained. It can spend 5 feet of movement to escape from nonmagical restraints or being grappled.

Unyielding Essence. The warden is immune to any spell or effect that would alter its form, as well as those that would read its thoughts or magically influence its thoughts or behavior. Creatures that attempt to communicate telepathically with the warden or magically influence its actions or mind instead take 14 (4d6) psychic damage.

Multiattack. The warden makes two melee attacks.

Slam. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

Sonic Boom (Recharge 5–6). The warden unleashes a sonic boom in a line that is 5 feet wide and 100 feet long. Each creature and object in that area must make a DC 19 Constitution saving throw, taking 26 (4d12) thunder damage on a failed save or half as much damage on a successful one. On a failed save, a creature is also pushed up to 20 feet away from the warden, knocked prone, and deafened until the end of the warden's next turn.

Destroy. The warden makes a slam attack against an object or structure.

Sniff. The warden makes a Wisdom (Perception) check using its sense of smell.

Immovable. When the warden is subjected to an effect that would move it, knock it prone, or both, the warden is neither moved nor knocked prone.