On Fire!

[On Fire! is a debuff which causes the afflicted NPC or player to lose 4 health per second and prevents regeneration. This debuff can be canceled prematurely by jumping into Water, or by pouring a Water Bucket over the player's head. If the player is under the effects of the Obsidian Skin Potion, Lava will not burn them.

Immune NPCs
Bosses: Other:
 * All Underworld NPCs
 * All Underground Hallow NPCs
 * All Snowman NPCs
 * Eater of Worlds
 * Skeletron
 * Wall of Flesh
 * The Destroyer
 * Skeletron Prime
 * Golem
 * Duke Fishron
 * Blazing Wheel
 * Crimson Axe
 * Cursed Hammer
 * Dungeon Guardian
 * Floaty Gross
 * Flocko
 * Giant Cursed Skull
 * Hell Armored Bones
 * Ice Elemental
 * Meteor Head
 * Mimic
 * Pixie
 * Possessed Armor
 * Present Mimic
 * Reaper
 * Wraith
 * Wyvern