Cult of Borem, of the Lake of Boiling Mud

The cultist touches one creature within 5 feet of it. The target must succeed on a DC 15 Dexterity saving throw or be coated in sticky, steaming mud. While it is coated in this way, the target's speed is halved, it can't use reactions, and it takes 10 (3d6) Fire damage at the start of each of its turns. The effect lasts for 1 minute, until the cultist is Incapacitated or dies, or until the target is immersed in water.