Dark Maw

Penumbral ichor drips from your shadow-stained mouth, filling your mouth with giant shadow fangs. Make a melee spell attack against the target. On a hit, the target takes 1d8 necrotic damage as your shadowy fangs sink into it. If you have a bite attack (such as from a racial trait or a spell like alter self) you can add your spellcasting modifier to the damage roll but not to your temporary hit points. 

If you hit a humanoid target, you gain 1d4 temporary hit points until the start of your next turn. 

This spell's damage increases by 1d8 when you reach 5th level (2d8), 11th level (3d8) and 17th level (4d8).