Craw Wurm

Frightening Hunter. As the wurm moves, its enormous body crushes trees and other plants in its way, creating a deafening roar. Any creature which can her the wurm when it moves must succeed on a DC 15 wisdom saving throw or become frightened.  The creature may make another saving throw as an action during each of its turns, ending the effect on itself on a success.  The creature has disadvantage on this saving throw if it can see the wurm.  If a creature succeeds on this saving throw, it becomes immune to the effect for 24 hours.

Oversized Body. The craw wurm's enormous size allows it to grapple up to three creatures at a time, so long as the creatures are of Large size or smaller.

Multiattack. The craw wurm makes one bite attack, one attack with its tail, and constricts one creature it has grappled.

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) piercing damage. 

Tail. Melee Weapon Attack: +9 to hit, reach 15 ft., up to three targets within 5 feet of each other. Hit: 15 (2d8 + 6) bludgeoning damage. and the target must make a DC 15 Strength saving throw or be grappled by the craw wurm.

Constrict. The craw wurm tightens its coils around one creature that it currently as grappled, forcing them to make a DC 18 Strength saving throw, taking 24 (4d8+6) bludgeoning damage on a failed save, or half as much on a success.