Cloudkill

Duration: 10 minutes, Concentration
You create a 20 ft radius sphere of poisonous fog
that spreads around corners. It's area is heavily
obscured. When a creature enters the cloud or
starts its turn there, it makes a Con save, taking
5d8 poison damage on a failure, or half as much
on a success. Creatures are affected even if they
hold their breath. The fog moves 10 ft away
from you at the start of each of your turns,
sticking to the ground. At Higher Levels. Each
extra spell slot