Cloudkill

You create a 20-ft-radius heavily obscured fog within 120 ft for 10 min.
Creatures inside: CON saving throw: 5d8 {p/g}, or ½ a success. Creatures are affected even if they hold their breath or don't need to breathe.

The fog moves 10 ft away from you at the start of each of your turns, rolling along the surface of the ground.

{x} 1d8 {p/g} per level.

“I release a wave of death from within, my spores spreading unseen, devouring all life in their path.”