Bosses

Bosses are large, aggressive, resilient enemies that offer a substantial challenge to players. Defeating bosses is usually instrumental in advancing the game in some way. Each has its own particular way of being summoned, and warning messages appear whenever one is about to appear. Defeating a boss concludes with a congratulatory message and several items. Most of the bosses can pass through blocks, with exception of King Slime, Lepus, Turkor the Ungrateful's body, and Golem.

During Hardmode, each night has a one in ten chance of spawning one of the three Mechanical Bosses that have not yet been defeated in the current world.

As of 1.3.0.1 all bosses have a unique icon on the map, which they now appear on.

Exclusively in expert mode the bosses has increased amount of health and damage.

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.

Hardmode Bosses
Hardmode Bosses are significantly harder upgrades of and new additions to previous bosses. Defeating them is usually instrumental in advancing the game in some way. Each has its own particular way of being summoned, and warning messages appear whenever one is about to appear. Defeating a boss concludes with a congratulatory message and several items.

During Hardmode, each night has a one in two chance of spawning one of the three Mechanical Bosses that have not yet been defeated in the current world. This only happens after removing at least one Altar from the world, so it may be advisable to refrain from doing so if the player is not ready for a challenging fight.

History
Boss