Hunger of Hadar

A 20-ft radius sphere of blackness appears,
centered on a point with range. No light, magical
or otherwise, can illuminate the area, & creatures
within the area are blinded and the area becomes
Difficult Terrain. Any creature that starts its turn
in the area takes 2d6 Cold Damage. Any creature
that ends its turn in the area must succeed on a
Dexterity saving throw or take 2d6 Acid Damage
Duration: 1 min Concentration
Component: a pickled octopus tentacle