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

Pack Tactics. The wolf has advantage on an attack roll against a creature if at least one of the wolf's allies is within 5 feet of the creature and the ally isn't incapacitated.

Corrupting Bite. On a successful bite attack, the target takes 2d6 poison damage and and is poisoned.

Multiattack: The Abyssal Dire Wolf makes three attacks, one with its bite and two with its claws.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 4) piercing damage. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be knocked prone.  On a successful bite attack, the target takes 2d6 poison damage and and is poisoned.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 4) slashing damage.

Distraction. If The Dire Wolf is in sharing melee combat range with an enemy and an ally, the Dire Wolf's ally may disengage from the shared enemy as a bonus action. 

Uncanny Dodge. The Abyssal Dire Wolf moves with unnaturally quick reflexes to avoid danger, and takes half damage from any attack or effect.