Adult Wind Howler

Saharan Camouflage. The Wind Howler has advantage on Dexterity (Stealth) checks made to hide in the sand or rubble. When surrounded by sand or rubble, the Wind Howler can hide as a bonus action.

Hypersensitive Hearing. The Wind Howler has advantage on Wisdom (Perception) checks that rely on hearing. In addition, the Wind Howler has advantage on attack rolls against a creature that spoke or made noise during its last turn, and was in range of its Blindsight. If the Wind Howler takes more than 40 thunder damage from a single source it is deafened until the end of its next turn. If the Wind Howler is deafened it loses this ability.

Debris Walk. The Wind Howler can move in difficult terrain as if it were normal terrain.

Preemptive Sense.  Any creature that makes a melee weapon attack against the Wind Howler and made noise on the same turn has disadvantage on the attack roll. The Wind Howler has advantage on Dexterity saving throws from spells that have a verbal component and were cast within its Blindsight range.

Sand Blind. The Wind Howler automatically fails Wisdom (Perception) checks that rely on sight or smell.

Multiattack. The Wind Howler makes three attacks: three with its claws or one with its bite and two with its claws.

Acid Reflux (Recharge 5-6). The Wind Howler projects a stream of bile in a 30 ft. cone. Each creature within range must make a DC 16 Dexterity saving throw. A creature takes 39 (6d12) acid damage on a failed save, or half as much on a successful save.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target: Hit: 23 (4d8+4) piercing damage. 

Claw. Melee Weapon Attack: +8 to hit, reach 10ft., one target. Hit: 15 (3d6+4) slashing damage.

Consume Flesh. The Wind Howler makes one bite attack against a creature that isn't a construct, elemental, ooze, or undead. On a hit, the target takes an additional 12 (3d6) necrotic damage, and the Wind Howler regains a number of hit points equal to the amount to the amount of necrotic damage taken by the target. Furthermore, the target can't regain hit points until the end of its next turn.

Rollback.  When a creature makes an attack roll against the Wind Howler and misses, the Wind Howler can move up to half its movement speed away from the creature, without provoking opportunity attacks. If the Wind Howler is surrounded by sand or rubble, it can then immediately take the Hide action.