You create a 20-foot-radius sphere of poisonous, yellow-green fog centered on a point you choose within range. The fog spreads around corners. It lasts for the duration or until strong wind disperses the fog, ending the spell. Its area is heavily obscured.

Creatures are affected even if they hold their breath or don't need to breathe.

The fog moves 10 feet away from you at the start of each of your turns, rolling along the surface of the ground. The vapors, being heavier than air, sink to the lowest level of the land, even pouring down openings.

As the spell concludes, a chilling fog unfurls, accompanied by a noxious scent. Amidst the yellow-green mist, spectral faces emerge, bearing silent witness—reminiscent, perhaps, of past spell victims. The haunting ambiance resonates with a distant, pained scream on the wind.

I Cast Cloudkill
With a whispered command, the air morphs into a green, foggy entity, reminiscent of winter breath. The ethereal serpent slithers, weaving into crevices, infiltrating every corner. A malevolent touch, it proves toxic, seeping through the pores of any living being it encounters.