Tunnel of Terror is a surprisingly simple DLC that just requires you to find each entrance in any random act you play through that isn't an end of a section like "T5" or "Act 4". All of the trophies are surprisingly easy, especially compared to the main trophy list of the game which requires a tedious and awful playthrough on Nightmare! You will just need to find a bunch of secrets, kill 3 new mutations and carry and kill with a few new items.

Time and difficulty are purely an estimate based on how long it may take to do all trophies if playing offline/offline. It may go quicker if offline, however, if AI/teammates kill new Ridden or you accidentally miss any secrets/weapons and make mistakes that may add time so that was put into consideration whilst doing this.

Entrances will randomly spawn on levels, so try looking carefully till you find the entrances. Please refer to  Master Spelunker to know what the entrances look like and which missions you can find them more easily in.

The recommended way to do this DLC is to do it offline so you don't join lobbies of people without the DLC, which can make killing enemies and getting certain trophies a lot easier.

Play on the easiest difficulty setting and decide whatever deck you think is best to use for this DLC but don't stress out or worry, because in this DLC you have early exits you can use to escape, just use them once you have gotten what you wanted and focus on getting every trophy possible since they can be done pretty quickly if you're efficient.

This trophy will require you to complete all 7 DLC hive missions in the game. Make sure to do them in the acts they appear in, or you will have to restart.

To find the hives you must go into any mission or act and try finding a hive a entrance on the map that looks like this:


These hive entrances can appear randomly on specific maps! However, if playing online, it will require people to have DLC so if the game joins you with someone who doesn't have the DLC, you will be wasting time, which is why it's recommended that you play offline since playing solo makes the game easier and matchmaking can be very slow. But it's up to preference how you want to play the new DLC.

To complete any of the hives towards this trophy, you can either take the optional quick end ladder during any point of the hives levels, or you can explore further into the levels and try finding secrets and weapon cases and loot. It is all down to personal preference how you want to go about the DLC. However, most of the secrets will be further down into the levels so only when you have got the secret and any other misc. trophies should you then go to an escape ladder.

If you die or fail these missions you can not return to them unless you re-find them! Depending on how long the mission is, whether you play online or not can heavily effect how long it takes to find the hive entrances, even offline depending on the mission you choose, you may need to do all objectives and find the entrance at the very end of level, or you may end up getting lucky and finding it near beginning or halfway, the location can be random on maps and can not be accessed through the games matchmaking/quickplay option so you get 0 chances to revisit these missions unless you find them in a random act mission.

Based on multiple playthroughs, there has been a clear consistency on getting certain hives to appear. Try using the table below to guarantee a hive entrance and to get the specific maps that have been found every time to do these specific acts to find the entrances.

Important information! Nursery Hives can only be accessed by finding another hive entrance in a hive you're in! So make sure to try searching for it on specific hives listed with a "+ nursery" on it since it's easier to find it in those specific levels.

Act To Find Hive	Hive Name
Act 1: 1 - 1 Resurgence, Act 1: 4 - 1 Bad Seed, Act 2: 2 - 1 Pipe Cleaners	300 Below
Act 1: 2 -1 A Clean Sweep	Caustic Cesspool + Nursery
Act 2: 2 - 2 Hinterlands, Act 3: 1 - 4 Garden Party	Blood Stream
Entrance found in hives only!	The Nursery
Act 2: 1 - 1 A Call To Arms	Brood Lair
Act 1 -2 - 2 Book Worms	Sunken Passages
Act 2: 2 - 4 The Clog, Act 3: 1 - 2 Blazing Trails, Act 3: 2 - 3 The Road To Hell	The Cut

To get this trophy, you must find a "Warped Chest" which will inflict 20% trauma damage and hope to find a Legendary (orange coloured) weapon and get a kill with it.These chests will be completely random in whether they will spawn in a hive mission or not and can only be found in hive missions alone. in order to access a hive you must find the entrance in any random mission of an act.

The easiest way to obtain this trophy is from "The Nursery" since you will start off with a ton of Warped Chests at the beginning of the level, making it super easy to get this trophy. However, it can be achieved in other levels if you are lucky in finding a Warped Chest since they can be hard to find.

Please refer to  Master Spelunker for more information on how to find specific Hive levels.

Warped Chest

To get this trophy, simply find 1 of any of the 3 Skull Totem in the DLC hives and bring it to the end of the level with you.

If you want to get this trophy as soon as possible you can use any of the early ladders to escape the hive with the Skull Totem or choose to keep exploring with the Skull Totem in hand.

Skull Totems can only be found in hives, which require you to play through a random act mission to find, then you must search through a level in order to actually find 1 of 3 of these totems to get the trophies related to them. While not hard to find, they can be missed if you do not search properly.

Bear in mind if you choose to continue further into the hives with a Skull Totem, it is a melee weapon that can be picked up and dropped and if you want to shoot or use other weapons you will have to drop the Skull Totem, so think carefully when deciding to go for these Skull Totems.

Please refer to  Using Your Noggin for more information on Skull Totems.

To get this trophy, you must get 10 melee kills with the Skull Totem in any of the hive DLC missions.The Skull Totem, besides being a collectible, is also a rare weapon that can be upgraded the more you find Skull Totems in the hive missions. There are a total of 3 Skull Totems in each hive and each time you pick up 1, it will upgrade your Skull Totem to a new rarity: Rare, Epic, Legendary.

Skull Totems can only be found in hives, which require you to play through a random act mission to find, then you must search through a level in order to actually find 1 of 3 of these totems to get the trophies related to them. While not hard to find, they can be missed if you do not search properly.
While you can go in with a melee deck if you choose to, it is not necessary as getting 10 kills is very simple and easy with this weapon because of how strong it is, which can help you quite a bit during the hives.

Skull Totem

To get this trophy you must kill all 3 new Ridden that have appeared in the game at any time during playing the game. It does not have to be done in a single match, but you'll need to kill all 3 over the course of your playthrough, else you will miss it.When it comes to killing the new Ridden be mindful of your AI/human partners potentially stealing your kills and making this harder to get, you will have multiple opportunities to work towards this trophy. However, the easiest way of getting these Ridden to consistently spawn and kill them is by doing either "Caustic Cesspool" or "Brood Lair" since they have all 3 mutations on the map.The new Ridden enemies will appear randomly as mob enemies. The new types of Ridden are the following:

Urchin

This Ridden shoots phlegm-like projectiles that strike targets and slows them down. However, they can be very easy to kill and won't be much of an issue. They can appear as a random spawn in the hives.
 

Shredder

The Shredder is a fat blobby enemy that will use its weird tentacles to drag you in towards it and then explodes on you after sucking you in. On higher difficulties this guy can be a very serious threat due to his large health and explosive damage. This can make killing them very awkward because if they self explode you will void the chance to kill it, so make sure you can put in fast and powerful damage before it uses its tentacles and explodes after dragging the player.
 

Ripper

The Ripper is a bruiser-like enemy that can ground pound and make spikes come from the ground. It can be quite tanky and take a lot of shots/hits to kill but isn't as dangerous as a Tallboy or a Bruiser in terms of abilities, so it's almost the weakest of the bunch. The best strategy with any of these Ridden types is to keep your distance and shoot its weak spot to quickly kill it.
 

Please see  Pipe Dream for more information.

Please see  Pipe Dream for more information.

Please see  Pipe Dream for more information.

Please see  Pipe Dream for more information.

Please see  Pipe Dream for more information.

Please see  Pipe Dream for more information.

To get this trophy and all the other secrets, you must find all secrets in each of the 7 DLC hive missions.

The reason why this trophy is missable is that if you can't find the hive, you will have to go back to a random mission. Try finding the hive and hope that you do not miss some of these collectibles, as there are some sections you can not go back or return to, so be very careful when following the guide or you may lose out on this trophy.

Secrets are exactly the same as the secrets in the main game but you must find them in the DLC hives, follow the video below and you should be able to get all the secrets needed towards your competition!

All Secret Locations Video Guide

Credit to AchievementSquad for the video.