Create a 20-ft-radius sphere of poisonous yellow-green fog (Concentration, 10 min). It spreads around corners and moves 10 ft away from you each turn. Creatures that enter or start their turn in the fog make a CON save or take 5d8 Poison damage (half on success). The cloud sinks to the ground, hugging surfaces. Higher Slot: +1d8 per slot level above 5.