Bio
The Moon Lord is a Hardmode, post-Lunatic Cultist boss. He is the final boss of the PC, Console, Mobile, Old Chinese, tModLoader, and tModLoader Legacy versions of Terraria.

Spawn Conditions

The Moon Lord can be spawned by destroying the four Celestial Pillars or by using a Celestial Sigil in any world where Golem has been defeated. He will then spawn one minute after the status message "Impending doom approaches..." appears, or 12 seconds if spawned using the Celestial Sigil. After this message appears, the screen will go dim, the music will gradually become quieter until it goes silent, and all objects and walls will oscillate back and forth. It will then go back to normal. This will happen 5 times; each time the screen will go darker and all objects and walls will oscillate more violently until the 5th time, when Moon Lord will spawn.

Stratigies
• Boss battles can be won or lost before the battle ever starts. Choose your equipment and have it ready; find and/or make potions and placed buffs; use the highest-tier food you have available; set up an arena appropriate to the boss; learn the strategies for the boss you're facing.
• Prepare your Boss-fighting arena with adequate lighting, Campfires
• Sunflowers provide the Happy! buff to players within a 50-tile radius, which grants a +10% movement speed bonus and 17% reduction in enemy spawn rate.
• Always carry around a stack of the highest-tier healing potion available, as relying only on natural Health Regeneration is not a good idea. Depending on the game stage, this can include items such as Mushrooms or Honeyfins. On the PC, Console, Mobile, and tModLoader versions, Restoration Potions are healing potions with a shorter cooldown.