Cloudkill

Description
A billowing cloud of noxious vapours settles over the area. Its effects vary according to the Hit Dice of the affected creatures: 1-3 HD: Instant death 4-6 HD: Fortitude save or death; 1d4 points of Constitution damage if save is successful Over 6 HD: 1d4 points of Constitution damage

Victims inside the spell's area suffer the effects each round. Undead creatures are immune to this spell.