Celebrationmk10

Celebrationmk10 is a secret world seed introduced in the 1.4.2.3 update. This seed celebrates Terraria's tenth birthday, May 16, 2021.
The following seeds can be used to generate a Celebrationmk10 world (case-insensitive): 
Please update this page for 1.4.4 additions
== World generation changes ==
=== Overall ===
* The spawn point can be on the left or right edge of the world, implying most of the spawns usually happening in the inner third of the world will happen in the left or right sixth of the world.
* Andrew the Guide, Whitney the Steampunker, Yorai the Princess, a Party Girl, and an Angora Town Bunny will also spawn there and a Party immediately starts.
* A majority of the world is painted: The Dungeon is in deep pink, Living Trees, the Pyramid, and Clouds on Floating Island are painted in pink, the Jungle Temple is painted with purple tiles and cyan walls, and all Sand Blocks, grass, and surface objects are painted in cyan.
* There are even more Living Trees than in a drunk world.
* Items in Chests always have a "best" modifier.
** Accessories will have one of the +4 modifiers (Lucky, Menacing, Quick, Warding).
** Weapons will have modifiers with the most stat increases, according to their damage type. The possible modifiers are:
*** Legendary, Godly, or Ruthless for melee weapons
*** Unreal, Demonic, or Ruthless for ranged weapons
*** Mythical, Demonic, or Ruthless for magic and summon weapons
**** Note that this generation is beyond the "modifier limit". For example, it is possible to get a flail with the Legendary modifier, which is impossible in a normal world.
* Half of the Underground Cabins have their tiles and walls replaced with Rainbow Bricks, and a half of the remaining ones are painted with a diagonal rainbow pattern.
* Gem Trees are more common, similarly to the drunk world.
* All Floating Islands have Hallowed grass and a Hallowed Water Fountain.
* Shimmer replaces all water in the underground on the same side as the Jungle.
=== Desert ===
* The Desert generates without its usual entrance but with a single Pyramid.
* The Chest in the Pyramid always contains a Pharaoh's set in addition to its normal loot.
* The caves of the Underground Desert are smaller.
== Other changes ==
* Two unique enemies can be encountered in this seed: 
** The Jungle Mimic can be found in the Hardmode Jungle.
** Golden Slimes can rarely spawn.
* Fairies are less rare and most of them are Pink Fairies.
* Uncommon and rare enemies seem to have a higher spawn rate.
* Hearts and Stars can always spawn as their seasonal variants.
* All Fallen Star projectiles (including those from the Star Cannon, but not those from the Super Star Shooter) are pink.
* The chance for a Blood Moon to occur is raised from to per night.
* The chance of obtaining a Rod of Discord is raised from to .
* Fireflies and Butterflies are more common.
* The chance of obtaining a developer set from a Treasure Bag is doubled.
* The chance for nights with an increased Fallen Star rate is doubled.
* More clouds spawn in the background and more of them have a special shape.
* The Steampunker and the Princess can always spawn.
* Vanity Trees are much more common.
* Most bosses (including the Celestial Pillars and the bosses' minions, but except the Leeches, Servants of Cthulhu, King Slime, Queen Slime, Plantera, Golem, Betsy, Lunatic Cultist, and the Moon Lord) are smaller than normal.
* The Traveling Merchant always sells 2 more items than normal.
* The Princess sells rare items:
** Slime Staff
** Heart Lantern
** Flask of Party
** Sandstorm in a Bottle (while in the Desert)
** Terragrim (during a Blood Moon)
** Pirate Staff (after beating a Pirate Invasion in Hardmode, during the following moon phases: )
** Discount Card (after beating a Pirate Invasion in Hardmode, during the following moon phases: )
** Lucky Coin (after beating a Pirate Invasion in Hardmode, during the following moon phases: )
** Coin Gun (after beating a Pirate Invasion in Hardmode, during the following moon phases: )
* The Wizard Hat grants an additional minion slot.
== World icons ==
The world icon of a Celebration world is a Pink Sakura tree with a bowknot.
File:IconCorruptionAnniversary.png|Pre-Hardmode Corruption world icon.
File:IconCrimsonAnniversary.png|Pre-Hardmode Crimson world icon.
File:IconHallowCorruptionAnniversary.png|Hardmode Corruption world icon.
File:IconHallowCrimsonAnniversary.png|Hardmode Crimson world icon.
== Tips ==
* Starting with the spawn at the Ocean makes the game easier if the player is on the Dungeon side but much harder if on the Jungle side. It may be worth generating a new world if starting on the Jungle side.
* Due to the way certain invasion mechanics work, Goblin Scouts and Martian Probes will spawn in the middle of the world, rather than the edges. Note that invasion events like Goblin Army will take place near the initial spawn point or Town NPCs, so in Celebrationmk10 worlds they will take place at the Ocean which the player spawned at by default.
* Since this seed increases certain drop rates, items in chests spawn with the best modifier, and NPCs sell more items, this is a very good seed for World farming and finding rare items.
== Trivia ==
* The names of three of the starting NPCs in the Celebrationmk10 seed are the names of three members of Re-Logic: Redigit (Andrew), Cenx (Whitney), and Yoraiz0r (Yorai).
* Due to the fact that the Steampunker spawns right from the start of the game in Celebrationmk10 worlds, it is possible to buy the Jetpack, a post-Mechanical Boss wing before a single boss has been defeated.
* Due to the way Celebrationmk10 seed is implemented, the list is not exhaustive and any number of 0 can be added before the number seed. Also many other unintended seeds have the same result, like (case sensitive):
** "Thirst of dress", "engineer governor reproduction" and "inform Representative yorai" produce a celebration world.
== References ==