Call of Duty: Black Ops 4

Pretty much, if you know how to get all these you should be fine, if not, I will try and explain where and how to get all of them!

NOTE: It appears to void the achievement if you upgrade any of the items so when going for this achievement, don't upgrade any of them! Adding on to this, you will not be able to unlock this achievement on Casual as part of the spoon step requires you to see numbers in which don't appear on casual!

Hell's Retriever

There is 3 dogs you have to fill up with souls around the map. One is at New Industries (near spawn), second spot is the same location as Black Ops 2 which was Cell Block 2nd Floor and the final location is right outside of the Warden's Office. To start collecting the souls all you need to do is kill a zombie next to the dog symbol (hard to miss) and keep feeding it souls until the dog disapears leaving the symbol on fire. Do this for all 3 locations and take the Underground Passages fast travel that can be found in wardens office or showers and about mid way through the travel you'll see the hell's retriever floating so just press 'X' when ar it and you should pick it up. Video reference if needed:

Spoon

For the spoon, you will need to get the shield as it requires you to use the shield to see a set of numbers and shoot souls at two things as well as the Hell's Retriever. Once you have a shield go to the wardens office and where the perk machine is, look the complete opposite way of the perk machine, pull out your shield and press 'LT' and you should start to see 3 numbers (two on the pillars and one on the back wall), note down these numbers with the first number being the one closest to perk machine and last being one on the wall. Head down to the Citadel Tunnels, at the bottom of the spiral staircase you'll see a box on the wall you will be able to open, in which you want to shoot it with your shield (use shield to absorb 3 souls by pressing 'RT' with shield out) and then 3 numbers will show up. Basically input the numbers that you have into that box (just press 'X' to advance a number) and once you have sucsessfully inputted the numbers, the elevator should fall down to the bottom signalling you have completed it correctly. Finally head to the docks, right where you can see the ocean you'll find a power switch which you'll have to shoot with your shield again. A crane should start moving, once it stops you want to throw your hell's retriever at the spoon which will be hanging out of the net that the crane just pulled over, the spoon will drop on the crate right below, just head up to it and press 'X' and you'll have the shield!

Video reference if needed:

Blundergat

There is two ways you can get a blundergat:

1 - Test your luck with the random box
2 - Mini quest to get a free blundergat

Video reference for free blundergat (better to watch then me explain in text ;) ):

Tommy Gun

Easiest of the bunch, it's a wall buy at the docks same place as it was in Black Ops 2, complete opposite side of where the work bench is. Or you can just pull it from the mystery box if you're trying to get the blundergat out of the box as well! Make sure to remove any attachments/death effects from the Tommy Gun as they appear to make the achievement void.

Once you have all of these equipped, the achievement should unlock!