Barroth

Mud Armor.
Barroth begins the encounter coated in thick mud. While coated, it has resistance to nonmagical bludgeoning, slashing, and piercing damage. This mud layer can be removed by taking 30 or more fire damage in a single round or by using three successful attacks with slashing weapons.

Charge.
If Barroth moves at least 20 feet straight toward a creature and then hits with a Head Slam attack on the same turn, the target takes an extra 13 (2d12) bludgeoning damage and must succeed on a DC 16 Strength saving throw or be knocked prone and stunned until the end of Barroth’s next turn.

Tunnel Sense.
Barroth can sense vibrations in soft ground or mud. It has tremorsense out to 60 feet while on natural ground.

Multiattack.
Barroth makes two attacks: one with its Head Slam and one with its Tail Sweep.

Head Slam. Melee Weapon Attack: +9 to hit, reach 10 ft., one target.
Hit: 17 (2d10 + 6) bludgeoning damage.

Tail Sweep. Melee Weapon Attack: +9 to hit, reach 15 ft., all creatures in a 15-foot cone behind it.
Hit: 14 (2d8 + 6) bludgeoning damage. Creatures must succeed on a DC 15 Strength saving throw or be knocked prone.

Mud Flail (Recharge 5–6).
Barroth slams its body into the ground, releasing a torrent of mud in a 20-foot cone. Each creature in the area must make a DC 15 Dexterity saving throw, taking 18 (4d8) bludgeoning damage on a failed save, or half on a success. On a failed save, a creature is also restrained by sticky mud until the end of its next turn.

Burrow Rush (Recharge 6).
Barroth burrows underground, re-emerging up to 30 feet away in a line, creating difficult terrain in its wake. Each creature in that line must succeed on a DC 15 Strength saving throw or fall prone and take 13 (3d8) bludgeoning damage.