Dagon exhales a 60-foot cone of inky blackness. Underwater it is as black ink, while above water it manifests as a thick cloud, and the area counts as heavily obscured. It remains until dispersed by a strong current or wind (at least 20 miles per hour). Dagon can end this effect on its turn as a bonus action. Creatures who enter or begin their turn in the area must make a successful DC 22 Constitution saving throw or take 18 (4d8) poison damage.