Boss & Event Lore

This page is meant to add a vague storyline to Terraria, both vanilla and fan. Feel free to add your own ideas, and have fun writing your own lore for your own bosses! There is also Boss Progression, for your convenience.

King Slime
Ah, slimes. The most looked down and inferior kind of life on Terraria. Most slimes usually stay small, only devouring small critters such as bunnies and birds. One day, though, a most peculiar slime rose out from the ground. This slime was exceptionally big, being 10 times larger than its minuscule family. As some may know, when slimes are born, they get an unstoppable, 24-hour desire to eat as much as it can swallow. As baby slimes are smaller than its parents when it is born, this usually stops it from eating its guardians. This gigantic slime, though, began eating everything in its way, and soon the local population of slimes was almost totally eradicated. The remaining slimes ran away and hid in different biomes, changing their color to hide from the gargantuan slime. Bigger things have to eat more, so the 24-hour hunger turned into a 48-hour hunger, and that turned into a 72-hour hunger, and vice versa. A king around the corner was scared that the beast would threaten his kingdom, so he sent his most trusted and skilled ninja to catch the slime. They had a long battle, for the slime knew how to split into two, and had an understanding of teleportation, from all the slimes it devoured. The small minds of the slimes it had slain came to piece together, giving it a rather large brain. Finally, the slime triumphed. But, the slime had never eaten humans before, and the slime found it rather hard to digest, so it eventually decided to just keep it in its body, as a trophy.

Eye of Cthulhu
Once, the Dark Lord (Moon Lord) had ruled the entire world, overseeing everything that happened. One day, a rebellion broke out that was consisted of almost all demon eyes. The reason is still being disputed by historians. The Moon Lord popped out one of its True Eyes, and sent it to intimidate the rebellion. The Eye, though, wasn't used to the life force of the earth, and it mutated the Eye, making it just a gigantic Demon Eye. The Eye was also not invincible anymore. It forgot what it was here for, and befriended the Demon Eyes instead. Over time, it became guardian of the night monsters, and attempted to stop anything or anyone that was too strong for its own good, for athough the EoC never went back to its master, it always would remain loyal to him.

Eater of Worlds
Worms, mostly harmless. There are some larger ones, capable of harming you. But what if a worm got corrupted? Summoned when three of its prized relics are smashed or attracted with rotting meat, the Eater of Worlds got its name from all the adventurers slain by it, from so many worlds. Legend says that if the monster is slain, a rift in time and space may occur...

Brain of Cthulhu
The Crimson. A dark and bloody place full of terrifying monsters. The mastermind behind it all? A brain. Hidden deep inside the caverns of the Crimson, this amalgamate was formed by fusing crimson altars together and attaching a heart inside of it. Legend goes that if someone, brave or foolish, holds a spine of some kind, the Brain will rise, attempting to destroy the person seemingly mocking it with the fact that it doesn't have a spine. If this bloody mesh of flesh is killed, the order of space and time may be disrupted...

Skeletron
The dungeon's official guardian, this monster has cursed an elderly man to become a vessel for its dying spirit, attempting to lengthen it's 1,000 year lifespan. The skeleton inside may be evil in some perspective, but just like the EoC, it is just trying to stop anyone that is getting too much power. If its vessel is destroyed, it will reach out and attempt to find another one...

Queen Bee
One familiar thing always goes with another, such as Peanut Butter & Jelly. Beehives are no exception. Where there is a beehive, there are bees. Just stay away from the larvae and you'll be fine.

Wall of Flesh
The underworld was once only inhabited by demons, who guarded the treasure deep within. They had a very powerful kind of magic. However, some only saw that magic as a tool to cause trouble. Eventually, an adventurer brave enough to explore the underworld, found a bit of the magic, and used it to bind a young man's soul to a doll. But as the adventurer came back down and threw the doll into the lava, he had awoken a creature, a wall made of human flesh. As much as the adventurer tried to run, he eventually devoured by the wall. Nowadays, only the bravest adventurers were brave enough to venture down and sacrifice the young man's soul to summon the beast once again, and few have managed to defeat the Wall of Flesh.

Mechanical Bosses
As the player has beaten more and more entities, it was impossible to ignore. Moon Lord, noticing that you, someone who once attempted to usurp him has grown more powerful, he has released multiple failed inventions at you, to attempt to make sure you fail once more...

The Destroyer
The Destroyer is a failed robot based off the design of the Eater Of Worlds, which was made to mine for resources in the ground which may have aided the Moon Lord in spreading his beliefs. However, the AI went rouge, forcing cultists to lock up The Destroyer. However, now the Moon Lord has released it in an attempt to send you into the abyss of death...

The Twins
After the Eye of Cthulhu mutated, Moon Lord requested a replacement to be invented. As such, the all-seeing Twins were built, with a laser module and a flamethrower module. The Twins started off with great success, but then, their AI went rouge. After the near-destruction of multiple lunar-based cities, the Twins were locked up. However, now they roam the skies of Terraria, seeking a worthy opponent.

Skeletron Prime
As the Moon Lord seeked to expand his influence, he wanted to create a machine of pure brawn. As such, he based it off the demon of the underworld that possesses the elderly. However, while it was only 85% complete, it broke free, and killed many cultists before being sealed. However, now it seeks to destroy whatever it finds on Terraria.

Plantera
Over the years, the ecosystem of the underground jungle has been through quite a lot of trials and tribulation. There was one time, though, when it almost came to a collapse. That was when the souls of light and dark were released into the world upon the defeating of the Wall of Flesh. The corruption started spreading rapidly towards the jungle, and threatened to corrupt it, too. The tree nymphs, sensing the great power of vileness and death nearing, awoke and created a kind of bubble shield with their life energy. The nymphs sacrificed themselves and released all their life energy, protecting the jungle. Their souls eventually made their way into the Great Jungle Flowers. Now, the nymphs live on in the form of the Jungle Flowers. They are usually docile, but beware. These Flowers one day will awaken their power once more when a certain thing gains too much control over the world, namely, defeating the Mechanical Beasts.

Golem
You remember those lizhards? Well, they build an idol to worship. Being made of impenetrable lizhard stone, it was indestructible. When the human entered the temple, they sent out their idol. Being fitted with ancient lizhardian technology, it was seemingly undefeatable. It had one major flaw, though: It couldn't fly. The Lizhardians just had to hope that the human didn't have any means of flight, either.

Duke Fishron
The monster of the depths comes out of the water to drag fishermen to the bottom. It was created, when a lab accident mixed the DNA of a shark, pterodactyl and a boar, creating a hybrid. The hybrid was exposed to radiation, when it escaped. The scientists tried tracking it, but failed. Multiple people have seen it's offspring, but nobody knows how it happened.

Lunatic Cultist
The cult of the Dungeon spent many of it's days enforcing the rule of the Moon Lord and worshipping them. Whenever a threat to the Moon Lord would arise, the Lunar Cult would step in to stop it. However, nothing is known about the leader, other than he is the oldest of the cult. This leader is the Lunatic Cultist. If anyone intervened for any reason in the affairs of the Moon Lord, and their affairs, the Lunatic Cultist would seek blood.

Celestial Events
Killing the Cult would enrage the Great One. He would send four (five, counting the one here) pillars with their exclusive enemies to try and stop the Human from discovering him. You see, the Great One was never attached to the Cult. He just wanted to use them as a seal to stop the human from discovering the Celestial Pillars. Should the Human destroy the Pillars, the Great One would have no choice but to face the Human himself.

Moon Lord
The Moon Lord, the great old one. Cthulhu's "brother". Nobody knew what he was, until a group of cultists found the beast. The beast of titanic proportions, the tyrant of a beast. Soon cultists started worshipping him, promised a fraction of his might and power. A few have seen the cult, but what is odd is that they say that there's a cultist with a bird mask, the leader. Nothing else is known of the beast.

The Necra
She is a human, who found the potential of the corrupt and bloody energies of Terraria. She was once a young girl in a small village who went by the name of Raven. However, she was shunned for her odd way of seeing things, she saw power in everything she looked at. One faithful day, years after she ran away from the village, she came across the Corruption and Crimson. Seeing the power in both of them, she tried to harness it, eventually succeeding, and she became the human that is now known as The Necra.

The Motherboard
As more knowledge and more efficient creations were required by the Moon Lord, he figured out that a supercomputer would do the trick. And after it became based off the Brain of Cthulhu due to cultists reporting seeing it, the Motherboard was born. However, it quickly turned rogue, and went on a rampage before a group of cultists sealed it away. However, now, it seeks to destroy the only things that pose a risk to it's continued existence. And you qualify.

The Peacekeeper
When push came to shove, the Moon Lord needed something to end scuffles. As such, he ordered an aerial weapon to be built to "keep peace". As such, based off what some cultists have seen in the Jungle, a mechanical queen of the bees was made, to create peace by destroying everything targeted. However, a few years into it's service, it thought a lunar city was a targeted city, so it completely destroyed the city. However, that led a group of cultists to seal it. However, now it roams the skies of Terraria, with you as it's target...

Wall Of Steel
When the cultists found out about a dangerous group of spirits, they came up with a way to reduce their powers. These cultists had all seen the Wall of Flesh, and then it hit them. They started building a machine based on the Wall of Flesh which would drive them all to insanity, and would stop the on-going war everywhere on Terraria. It worked. However, if one being was to grow powerful enough, the Wall of Steel would detect them as a spirit and attack them. If that happened, the war over Terraria would begin once more, and the Spirits could once again plot to become free once more...

Earth Lord
After the grand split of The Phantom, the Earth Lord was the counterpart to the Moon Lord. It quickly grew attached to Terraria and other celestial bodies. As such, when the Moon Lord created his cult, the Earth Lord created the Cult of the Sun. As the Moon Lord grew more powerful, so did the Earth Lord. However, now that the Moon Lord is dead, there is now an imbalance. And since you once rebelled against all cultists, Earth Lord is now coming for you...

Growl and Groan (Mini-Bosses)
When the cultists sealed the Spirits with the Wall of Steel, they knew that there should be a back-up seal in case a being destroyed the Wall of Steel. As such, a tablet was created to seal the power of the Spirits instantly if the Wall of Steel was destroyed. However, just the tablet being there was obviously a great risk, so two of the strongest cultists agreed to guard the tablet if anything wished to destroy it. As such, they will fight anything that tries to destroy the tablet, even if their intentions are good.

The Phantom
The universe was once a clean slate. Then, suddenly, one thing appeared. That thing was the Phantom. It was the first being in a blank and unchanging universe. The Phantom quickly grew lonely, so it went on a search for someone, something to be friends with. Then, it figured out there was nothing. So, tapping into it's immense power, there was light, and expansion. However, what the Phantom had just done put a toll onto it's body, and it split into two. The lord of space, the Moon Lord, who quickly found a brother in Cthulhu, and the lord of all bound to a spherical body, the Earth Lord. Both would wind up doing things to the universe in their own right. However, if someone wound up killing both of the lords and releasing the Spirits into the wild, the Phantom may find a way to come back again to a world which now opposes it's very presence...

Parascyte
Elysius had always had a fascination for the great jungle flowers, the alpha species of the underground jungle. While certainly strong enough to defeat one himself, he knew it would benefit him little capturing an individual. However, using previous experiences with the great flower, he devised a plan. Sending Kragon out to locate a dormant bulb, outfitted with a nano-parasitic machine designed to be implanted onto the dormant flower. It would leech of the infant, sending back information to be processed by S.C.A.R. This device, which would later be referred to as a "Parascyte", still continues to feed back information to Elysius' Lab, that would be, until it's host were to, I don't know, died?

Alyssika
Alyssika grew up in a small isolated community close to the dungeon, and as such, unlike many people, was unnerved by the sight of the place that once held so much death and haunting. Growing up, she learned of the town's protection under Skeletron, and how that every 3 years, they would sacrifice one of their one to please the demon and in turn, it would grant them a fragment of his demonic strength. However, when the Cultist and his followers made the dungeon his own, they laid waste to the town, killing Alyssika's family and everything she knew. Despite having survived, she was a hollow, empty shell of herself, devoid of any meaning. However, when the scientist Elysius had stumbled upon the ruins of her town, seeking knowledge from Skeletron and the town that it once protected, all he discovered was a lonely, starving girl sitting amongst the charred ruins. Pitying her, in an act of kindness never seen before in the power-hungry scientist, he offered her a deal: He would provide her shelter, and in turn, she would serve him as his assistant in his quest for absolute knowledge. Accepting the proposal, she oversaw many of Elysius' brutal experimentation and tests, and in turn became one of the deadliest weapons in Elysius' hunger for knowledge, and one of few he truly had respect for.

Boss Progression
(Placeholder boss progression until a template is figured out, update this if needed. Please add lore alongside any new entries here.)

Pre-Hardmode:

 * 1) King Slime
 * 2) Eye of Cthulhu
 * 3) Eater Of Worlds/Brain of Cthulhu
 * 4) Queen Bee
 * 5) Skeletron
 * 6) Wall Of Flesh

Hardmode:

 * 1) The Destroyer/The Motherboard
 * 2) Skeletron Prime
 * 3) The Twins
 * 4) The Peacekeeper
 * 5) Plantera
 * 6) Golem
 * 7) Duke Fishron
 * 8) Lunatic Cultist
 * 9) Moon Lord
 * 10) The Necra
 * 11) Wall of Steel

War Mode:

 * 1) Earth Lord
 * 2) Growl and Groan (Mini-bosses)
 * 3) The Phantom

Credits

 * MartinPlayZ2435 did Duke Fishron and Moon Lord.
 * ImARandomGamer did Wall of Flesh and The Necra. Thanks to both of you!
 * Inferno Gear (Real Inferno Gear) did the Phantom's lore, the Motherboard, The Wall of Steel, The Earth Lord, and rewrote the lore of the Mechanical Bosses and of the Lunatic Cultist..
 * Everything else is made by J13.