Terraria 1.4.5 all 22 new achievements guide

Book Worm
Get all bestiary entries (546) 1.4.5 added 6 new entries and they are:

• Pufferfish: A critter that spawns in the ocean
  
• Orca: Spawns in the ocean, throw chum to raise it's spawnrate
  
• Statue: Spawns in the graveyard disguised as a statue block. Quite rare. You can only damage it if you get close and it attacks you. Hunter potion highlights it.
  
• Moss Zombie: Spawns in the graveyard biome if you have low luck. Killing ladybugs reduces luck. Quite rare.
  
• Librarian Skeleton: Spawns in the dungeon in pre-hardmode near books.
  
• Water Bolt Mimic: Spawns in the pre-hardmode dungeon. Not that common.

Boulder Lord

Defeat the Moonlord in Get fixed boi. It's preferred to use a post moonlord character to do so.

Queen Machine

Defeat Mechdusa, spawned using Ocram's Razor in only the Get fixed boi seed.

Rollin' in Your Grave

Ride on a Coffin Minecart

Fear the Sun

Wear the full Vampire vanity set first. Next, type in the seed: "what a horrible night to have a curse/whatahorriblenighttohaveacurse" and go outside during the day.

It's Shaling Outside

In a For the Worthy + Drunk Seed combo world, a boulder rain happens instead of a thunderstorm sometimes. (you can easily start one with journey mode)

Extra Life

Die as a hardcore character in a Celebrationmk10 + The Constant combo world

Grave Mistake

Kill another player/NPC with your tombstone. Tombstones only do damage in Get fixed boi. Use a flymeal/lava to damage an NPC, make sure they're in a box, and die in the box so your grave splats them. Make sure there is no where the grave can become a solid block or it'll most likely fail.

Spicy Licks

Swing a guitar such as The Axe, Ivy, Rain song, etc

Organized Chaos

Obtain a Rod of Discord, an extremely rare drop from chaos elementals. Use Luck buffs and spawn rate increases to help, making a farm is something you should do too. If you already have one, dropping and picking it up will get you the achievement

On Fleek

Wear Sunglasses, crafted from two black lens, a rare drop from demon eyes. For me I had to rejoin for it to grant the achievement.

Fortune Favors the Bould

Activate a Rainbow Boulder which is made with one Boulder and 50 fallen stars at a Crystal Ball. They naturally generate in some secret seeds too.

Training Day

Use Advanced Combat Techniques, an item obtained from fishing during a bloodmoon, and Advanced Combat Techniques: Volume Two which is obtained by throwing a Spell Tome in Shimmer

Mini Me

Wear a Moon Lord Mask, Moon Lord Chestpiece, and Moon Lord legs. Moon Lord mask is an uncommon drop from the Moon Lord, Moon Lord Chestpiece is obtained from Gold Lock Boxes in For the Worthy, and Moon Lord Legs are from chests in drunk world/Get fixed boi

Terrarist

Hit an NPC with the Flymeal, a sword crafted from a gold/platinum broadsword and five stinkbugs near honey.

New Digs

Drop an NPC in Shimmer or use the new Shimmer gun (made from shimmering a slime gun) to change their appearance

My People Need Me

In a Get fixed boi world, fly to the world height and keep going

Going Oldschool

Grab the sun/moon and move it to the middle of the screen in the title screen

Sea You Later

Craft a Shellphone, an item that is made with a Magic Conch which is obtained from desert chests, a Demon Conch obtained from lava fishing, and a Cell Phone

Trash Compactor

Research 50% of all items in Journey Mode. Besides items you'll get on a normal playthrough, it's recommended to pick up everything you see, chandeliers and paintings in mineshafts, any item. There are a ton of furniture and platforms and walls, try researching them. Rare items or items that will take a long time aren't worth it.

Conservationist

Simply obtain and plant 100 acorns, the trees don't need to grow

Interdimensional Recycling

Obtain a Joja Cola from fishing. Joja Cola is trash so you need <50 fishing power and a lake smaller than 300 blocks. Have the Joja Cola in your hotbar and selected, and talk to the Dryad and click "Purify" you'll get this achievement and a pet item!