Bosses

Bosses are aggressive, resilient enemies that offer a substantial challenge to players. Defeating a boss is usually instrumental in advancing the game in some way or another, for example, granting the player a new material for a pickaxe of a higher tier. Each has its own particular way of being summoned. For example, most bosses have associated summoning items that can be used to spawn them manually under certain conditions, while there are others that will appear after the player interacts in a certain way with the environment. Event bosses will only appear during their respective events and leave when the event ends. Mini-bosses also exist and appear only during special events, expressing the same amount of difficulty as many normal bosses. Their health has a huge range: On Classic Mode it ranges from 1,000 to 273,000.
Most bosses and mini-bosses can pass through blocks of all types, with the exception of King Slime, , , body, and the .
For all non-event bosses, with the exception of the , status messages will appear when that boss is about to spawn or has already spawned. Upon spawning, its particular theme music plays. During events, bosses and mini-bosses can appear multiple times and have no distinct spawn message. In the case of wave events like the Pumpkin and Frost Moons and the , status messages that appear at the start of each wave can indicate whether or not a certain boss or mini-boss will appear. Defeating a non-event boss concludes with a congratulatory message and several reward items.
On the , bosses will appear on the minimap, each with an individual map icon. On the , a boss health bar will appear on the screen. (Note that it will only show the health of the most recently-attacked boss, if there are multiple. This is most prevalent when fighting The Twins.) 
* However, bosses will still appear as the standard purple blob that signifies enemies on the .
*Bosses do not have their own banners.
All enemies that can spawn naturally have a better chance of spawning if the player stands near a placed Water Candle or while under the effects of a Battle Potion.
== Pre-Hardmode bosses ==
These are the first bosses the player can encounter. Usually, defeating one of these bosses will give the player items and materials necessary to progress in the game, eventually leading to Hardmode. Although there are 8 pre-Hardmode bosses, only 7 can be spawned in the same world, as Eater of Worlds is exclusive to worlds containing the Corruption, and Brain of Cthulhu is exclusive to worlds containing the Crimson (assuming the player does not place an alternate evil in the same world as the other one, e.g. via seeds from another world or seeds purchased from the Dryad NPC in Hardmode, and does not use a ).
== Hardmode bosses ==
Hardmode bosses are significantly stronger than previous bosses.
== Event bosses ==
Event bosses are classified as mini-bosses, except for the Celestial Pillars.
== exclusive ==
== exclusive ==
== Notes ==
* Boss classification is determined as follows:
** Bosses: boss = true in Terraria's source code;
** Mini-bosses: the other trophy-dropping characters.
* The status messages that appear when the bosses are about to spawn are as follows:
** Eye of Cthulhu: ""
** Eater of Worlds and Brain of Cthulhu: "" after the first and "" after the second Shadow Orb/Crimson Heart is broken. The third only produces a standard summon message.
** The Destroyer: ""
** The Twins: ""
** Skeletron Prime: ""
** Moon Lord: ""
* As of 1.2.3, worlds generated in earlier versions, in which a player defeated all mechanical bosses before upgrading, will not have those bosses register as defeated; for instance, Plantera's Bulbs will not spawn, and the Steampunker will not arrive.
* There are currently different/unique bosses ( , , , ) in the game.
* Many events and some locations have an enemy that is particularly difficult to defeat, yet is not classified as a boss. These include:
:
Enemy 	Environment
Dungeon Guardian 	Dungeon prior to defeating Skeletron
Hardmode 	Hardmode
Corrupt/Crimson/Hallowed/Jungle Mimic	Their respective biome
Wyvern 	Sky
Paladin 	Dungeon
Ice Golem 	Blizzard
 	Sandstorm
 	Blood Moon fishing, despawns at dawn
Hemogoblin Shark 	Blood Moon fishing
Blood Eel 	Blood Moon fishing
 	Solar Eclipse
Nailhead 	Solar Eclipse
 	Goblin Army
Pirate Captain 	Pirate Invasion
Headless Horseman 	Pumpkin Moon
== Achievements ==
== History ==