Shapechanger. The barghest can use its action to polymorph into a Small goblin or back into its true form. Other than its size and speed, its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. The barghest reverts to its true form if it dies.
Fire Banishment. When the barghest starts its turn engulfed in flames that are at least 10 feet high or wide, it must succeed on a DC 15 Charisma saving throw or be instantly banished to Gehenna. Instantaneous bursts of flame (such as a red dragon's breath or a fireball spell) don't have this effect on the barghest.
Keen Smelt. The barghest has advantage on Wisdom (Perception) checks that rely on smell.
Innate Spellcasting. The barghest's innate spellcasting ability is Charisma (spell save DC 12). The barghest can innately cast the following spells, requiring no material components:At will: levitate, minor illusion, pass without trace
Bite. Melee Weapon Attack (true form only): +6 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) piercing damage.
Claws. Melee Weapon Attack. +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage.