Bosses - Official Thorium Mod Wiki

The Thorium Mod expands on the number of bosses that can be challenged by players at various points in the game. With exception to a new final boss, each of the bosses added in the mod are strictly optional and cannot spawn naturally without the use of their respective boss summoning items (or alternative methods) to initiate the fight. However, defeating these bosses may be beneficial to players, as their drops supply additional powerful options to assist players with progressing further into the game. Additionally, they grant access to new Town NPCs who can provide helpful items and other services.

Bosses - Official Terraria Mods Wiki

I made a thing regarding why bosses attack the player, it has vanilla and thorium (I am not done with my first thorium playthrough, so I got what I beat so far).

Bard Loadouts Guide - Terraria Thorium Mod

Well the granite set looks awesome [thorium mod] : r/Terraria

The Thorium Mod on X: Have a little spoiler! Of course our bosses and mini- bosses need their Master Mode Relics. #Terraria #tModLoader / X

Terraria: Thorium Mod (2014)

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