Drought

You draw the moisture out of a creature's body, causing it to wither and dry up. Choose one creature within range that you can see. The target must make a CON 14 saving throw. On a failed save, the target takes 4d6 necrotic damage, and any water or moisture inside the target's body is immediately extracted, leaving the target severely dehydrated. The target's speed is halved, and it has disadvantage on ability checks and attack rolls until it drinks a gallon of water or receives magical healing.