In the latest update for Terraria, the 1.4.5 Bigger and Boulder update, plenty of cool stuff was added, but for my fellow completionists, a painfully large number of new achievements were created alongside all the new content.
There are 22 new trophies to collect, and they range from brain-dead easy to something even the most unemployed friend won’t wish to tackle. Plenty of these require that you’ve achieved everything that came before this, and have beaten the game multiple times
For this guide, I’ll assume you have all the achievements in 1.4.4 and have an endgame character to quickly grab new ones with. All that said, let’s jump into this, starting with the easiest ones first.
Going Oldschool

This is the easiest new achievement in the game if you know how to get it. Right after the game boots up, on the title screen, click on the sun. This reverts the title screen to how it was in the days of old, and has been in the game for years, but is only now an achievement.
Extra Life

To get this new achievement, you need to die. That is, you need to make a hardcore character go to a world that is the combo of Celebration Mk. 10 and the Constant in the Special Seeds Menu. In this world, pillar up with platforms and fall off, and you won’t actually die; you will just lose a ton of max life.
It’s Shaling Outside

For this achievement, go to a combination of the Drunk and For the Worthy seeds, and use a Journey mode character to speed this up. Firstly, build a box around you to protect yourself, then set Wind and Rain to max, and once the boulder rain clears, you will get the new achievement.
Fear the Sun

For this achievement, put “what a horrible night to have a curse” into the seed on world creation, then you’ll spawn into the Vampirism secret seed. If you already have a vampire set on hand, this will be extremely easy, but if not, you can find it in chests around the world.
You can also nab this set from Goodie Bags, so if you have those on hand, you should open them up. Once you have the set, put it on, then go to the surface, where you will begin burning up in the sun and be granted this new achievement.
My People Need Me

If you don’t have one already, create a Don’t Dig Up or Zenith world, then go through the lengthy process of climbing out of hell and getting to the surface. Go all the way up into space, and take a jump into the topmost world border, where you will be sent into orbit and get My People Need Me.
Grave Mistake

In either a For the Worthy or Zenith world, simply die a painful death next to either a town NPC or another player, whichever is more convenient. NPCs usually need to be weakened to die to a gravestone, but a defenseless player in Master Mode will almost always die.
To that end, I weakened an NPC with lava, put myself in a box with them, covered the floor in gravestones, and then died to lava myself. This made the gravestone bounce around and pretty much guaranteed a kill for the new achievement.
Conservationist

Onto one you will most likely get naturally, Conservationist makes you plant 100 acorns. If you don’t have a Journey character with acorns duped, first of all, you will probably want one, but secondly, you can just start a tree farm and have this done in under an hour.
Interdimensional Recycling

You may already have the Joja Cola from the previous update, but if not, then you should purposefully decrease your fishing power by fishing in a tiny pond, like you would if you wanted garbage in Stardew Valley. Doing this, you should get Joja Cola eventually.
Take the soda, hold it in your hotbar, and speak to the Dryad, then select “Purify”. Doing this gives you the new achievement, alongside a Stardrop that gives you a Junimo pet. If you already have this pet, then you will need to fish up another Joja Cola for this.
New Digs

For this new achievement, first, find the Shimmer in your world, which will usually be deep underground on the jungle side of the world, between the jungle and beach biomes. You can optionally grab a Slime Gun from the King Slime, as it will make this easier.
If you don’t have the Slime Gun, build an NPC house above the shimmer, wait for someone to move in, then drop them into the pool. If you do have the gun, drop that into the shimmer for the Shimmer Gun, then spray any NPC with it for the achievement.
On Fleek

For this new achievement, you need to wear Sunglasses outside while the sun is visible, to make it revert to a much older sprite where it is also wearing sunglasses. You craft these glasses with two Black Lenses, which are a rare drop from Wandering Eyes.
Rollin’ In Your Grave

To construct a Coffin Minecart, get 5 Iron/Lead bars, 10 of any wood, and 10 Vertebrae or Rotten Chunks, and combine them at an Anvil in a Graveyard biome. Afterwards, simply equip the Coffin Cart and take a ride on some rails for the achievement.
Fortune Favors the Bould

To get a Rainbow Boulder, either find one naturally or craft a Boulder together with 50 Fallen Stars at a Crystal Ball to make one yourself. Either way, once the Rainbow Boulder is placed and then broken, it will activate, becoming your best buddy and giving you a trophy.
Spicy Licks

There are a few ways to get this new achievement, all of which involve playing a guitar. You can get the Ivy by killing a Steampunker named Whitney, or the Rain Song from flying fish during rain. Either way, just strum on it once and get your reward.
Training Day

I hope you really like fishing. If you don’t already have both volumes of Advanced Combat Techniques, then wait for a blood moon, max out your fishing power, and start casting. Do note that using Crate Potions or the Chum Caster will make this take much longer.
After fishing up and using the first edition of Advanced Combat Techniques, getting the second one is thankfully considerably easier. Buy a Spell Tome from the Wizard, then take that to the shimmer, throw it in, and you now have both books for the new achievement.
Terrarist

For one of the wildest achievement names ever, you need the Flymeal, a sword that is crafted in honey, using a Platinum/Gold broadsword and 5 Stinkbugs. Stinkbugs only spawn randomly during the day, when it’s not raining, only on the surface, at low wind speed, and not in a graveyard, so good luck.
Once you get the crafting ingredients, go find a pool of honey and sit in it to craft the Flymeal, then use your pylons to seek out the NPC you hate the most. You only need to smack them with the sword once for the new achievement, but nothing is stopping you from taking out your frustrations.
Sea You Later

If you have already gotten every achievement in Terraria before this point, then this will be a pretty easy one for you, but if not, then enjoy getting every informational accessory, crafting the P.D.A, combining that with a Magic Mirror, and making the Cell Phone.
With the Cell Phone, all you need now are the two magic Conch shells. You can get the Magic Conch by either fishing in the Desert or finding it randomly in the underground Desert. The Demon Conch is acquired exclusively through fishing in lava. Combine all three of these things together to get Sea You Later.
Mini-Me

This one requires that you wear the full Moon Lord vanity set, which can be a pain to acquire. You can get the Moon Lord Mask on any seed by killing the Moon Lord and getting it as a rare drop, but the other two require that you hop into different Special Seeds.
The Moon Lord Legs are pretty commonly found in any chest in a Drunk or Zenith world, but the Moon Lord Torso is only acquired in the For The Worthy seed’s dungeon. If you don’t find it in the initial dungeon chests, you can fish for it in the For the Worthy dungeon.
Dungeon fishing gives you Dungeon Crates, which can give you Golden Lockboxes, and opening these on this seed has a chance to give the Torso, so if you have them researched in Journey mode, you can do that instead. Either way, equip all three in vanity slots and get your new achievement.
Organized Chaos

This one requires you to get the Rod of Discord, a notoriously rare drop, but there are quite a few ways to make this substantially less rare. Namely, make a combination Skyblock and Celebration Mk. 10 world, for Skyblock’s empty world and Celebration’s increased drop chance.
First off, go kill the Wall of Flesh, then go down to the Cavern layer and build a long, roughly 200 block wide Pearlstone platform. You can stop there and just stand in the middle with 10x spawn rates, or make a slightly more intricate mob farm, but either way, the rod should drop in a few minutes.
Queen Machine

If you haven’t beaten the Zenith seed previously, go ahead and speedrun the Wall of Flesh on it with an endgame character, then grab all three mechanical boss summons, and combine them at an anvil to get Ocram’s Razor.
Using this will summon Mechdusa, a fight that is really difficult if you’re actually playing through the seed, but folds easily to a Legendary Zenith and Solar Armor. Once you’ve killed all three mechs that comprise Mechdusa, you will get the new achievement.
Boulder Lord

Similar to the previous achievement, if you haven’t beaten For the Worthy or Zenith before, go ahead and speedrun one of the two with an endgame character. The Moon Lord fight in these worlds is enhanced with a big boulder attack after the top eye closes, so look out for that.
You can dodge this by just quickly falling downwards right before the attack hits, and then dodging all the boulders as they slowly fall. Kill off the Boulder Lord as you would any normal Moon Lord fight, and you get the Boulder Lord achievement.
Book Worm

When I saw someone ask Redigit to add a 100% Bestiary achievement on Twitter, only for him to say yes, it felt like watching a kid remind the teacher to hand out homework. Luckily, Terraria makes this new achievement somewhat manageable through the Bestiary Filters.
To start, go through the Filters for each biome, and crank up the spawn rates while cross-referencing the Wiki on what you’re missing. I’ll go over some of the trickiest ones, but this should get you 98% of the way there.
The wiki, while helpful for this, is also not entirely reliable. At the time of writing, entry 119 is mislabeled as Grubby, when it’s actually a Jungle Turtle, so make sure to double-check against the bestiary entries and look at the Wiki to find the enemy before the entry you’re missing, then see what comes after.
This is also a stark reminder that Bestiary progress is per-world, not per-character, so hopefully you’ve been thorough with killing things in your main world. First and foremost, get every Town NPC, as the Princess is one of the most often missed entries.

Santa Claus can only move in during Christmas with a vacant Snow Biome home after beating the Frost Legion, so make it either December on your PC Calendar or beat the Frost Moon. Similarly, enemies that spawn during Christmas and Halloween are also unique bestiary entries.
If you don’t have Fairies researched and have broken the Fallen Log in your world, you can either shake a ton of pearlwood trees at night in hopes of getting fairies, or world hop, catch fairies in a bug net, then go back to your main world, release them, and murder them.
Moss Zombies spawn on stone in Graveyard Biomes when you have low luck, so break some Pretty Mirrors and stand on Poo Blocks. Similarly, the Statue Mimic also spawns when you have low luck, in any biome, and usually on solid blocks.
Once you finally kill the last enemy you needed for your bestiary, the new achievement will unlock instantly. Just be thankful they didn’t force you to get all the Special Seed-specific enemies, like Jungle Mimics and all the slimes in Skyblock.
Trash Compactor

This is, personally, what I feel to be the most difficult achievement in the game, as it requires you to research 50% of all items in Terraria. The game won’t tell you your exact research progress, but luckily, this one is only character-dependent and not world-dependent.
If, like me, you ran through Journey mode already trying to research everything you came across, then further researched things as you completed every achievement up to this point, you probably have a sizeable dent in the progress.
I really wish there were a way to tell exactly how much progress you’ve made, but alas, the tool to do so does not currently work with 1.4.5 characters. That said, get the easiest things out of the way, place every crafting station in one place, and buy out every NPC shop.
In your big square of crafting stations, start by going through a bunch of materials. Every wood type, stone, every ore, every building block you already have researched, and keep going down your research menu for a while, crafting and trashing everything you don’t have researched.

As you go through the various building blocks, keep wood, stone, chains, glass, torches, and iron or lead in your inventory, as they usually have some joint crafting recipe with every block type. Keep in mind, there are 6000+ items in this game, so this will take forever.
Once you have gone through all the blocks, visit the materials tab and start working on those. This will give you even more blocks, which you now have to create more decor and walls with, and repeat the cycle until you either get the new achievement or can’t make any more things.
If you get stuck here, I’d recommend going to a Zenith world with a Celebration Mk. 2 equipped with Mini Nukes and going to town. This gives you a ton of resources you may or may not have had, alongside paintings and furniture that aren’t quite craftable.
Midway through crafting everything with my Gems and Bars, I got the achievement from crafting a Platinum Candelabra, and I’ve never felt so simultaneously upset, underwhelmed, relieved, and overjoyed. Thanks, Redigit, I hate it.
