operations SWTOR

The Writhing Horror–Terror from Beyond boss guide

This is the boss strat for The Writhing Horror, the first boss in SWTOR Terror from Beyond TFB Operation in Patch 1.4. Included are strats for both storymode and hardmode.


  • Writhing Horror – 957k (8M SM), 1.76 million (8M HM)
  • Jealous Male – 85k (8M HM)



Mechanics Strategy
Burrows in/out Tanks need to use their gap closers and leap/jump to the boss ASAP when he reappears. Otherwise he will spit stuff at the raid. You do not lose target when the boss disappears so just spam your gap closer as soon you see the boss pop up. There is a set pattern on where the boss will appear next after he burrows in.
Jealous Male & Foul Offspring Jealous Male and Foul Offspring spawns in the fight with a red text on screen. DPS/Healer need to be assigned to run to the red circle to “attract” the adds while a tank grab the Jealous Male
Tank Swap Tank swap on the main boss everytime you see the Jealous Male spawn. Boss puts a Incubated debuff on whoever tanking it.
Red Circles One red circle will spawn on the raid. It will usually spawn where the “flowers” are located on the ground. Don’t stand on the flowers unless you are assigned to red circle duty.
Corrosive Slime This is a hard ticking DoT (3.6k damage every 3 seconds) that can be cleansed

Things to do before the fight

  • Assign people on red circle duty (healer/DPS). You can’t have a single person doing it as he/she will receive a debuff when they exit the circle. Usually 4 players is a good number.
  • Learn where the boss burrows (see diagram below)
  • Learn the locations of the 3 flowers on the ground and don’t stand on them during the fight. One of them will become a red pool when the Jealous Male spawns.



There are two things to know about burrowing

  • There is a fixed pattern on where the boss spawns after he burrows
  • After he appears from the ground, he will spit at the raid unless someone has threat (i.e. tank) in melee range. Tanks will need to use gap closer on him ASAP. Failure to do so will cause him to spit at raid, causing raid wide damage.
  • The name of the spit is called Angry Spittle if you are tracking it via a combat log program (hits for 3k damage on hardmode)

This is the pattern he uses when burrowing. It is a 5 point star essentially. He will go back to point 1 and repeat the pattern.


If your tank is quick, you will get 1-2 spits on the boss from the boss maximum. The damage is fairly small and can be easily healed through.


Tank Swap

The tank tanking the boss will get stacks of a debuff called Incubation from the boss. This debuff doesn’t always land everytime (can be dodged) so you may get different stacks of it everytime. The maximum stack this debuff will go to is 10.


  • The number of stacks of Incubation determines how many Foul Offspring will spawn ( see below).
  • Incubation debuff will fall off if the Jealous Male hits the tank with it
  • If the tank has 10 stacks of the Incubation debuff, he may explode

Generally, we tank swap every time we see the red text emote for Jealous Male spawning.The tank that was on the boss would grab the Jealous Male and erase his stacks of Incubation to spawn Foul Offspring.

Jealous Male, Foul Offspring & Red Circle

Jealous Male is an add with a fixed spawn timer

  • First spawns 45 seconds into the fight (tank will usually have ~4 stacks of Incubation debuff here)
  • Second one spawns at 2:15 (1:30 from the first add, tank will usually have ~8 stacks)
  • Third one spawns at 3:45 (1:30 from second add)
  • Fourth one spawns at 5:15

There is a red text on your screen when he spawns – A Jealous Male Has Arrived to Defend His Mate!


When the Jealous Male spawns, one of the flowers on the ground will also turn into a red blood pool, this pool is used for the Foul Spring that will spawn right after.


Jealous Male has a cleave and knockback, tank him away from the raid. You should have the tank swapped here and have the tank with the Incubation debuff tanking him, this will spawn a bunch of smaller adds called Foul Offspring depending on the # of stacks of the debuff. Make sure the tank is not tanking the Jealous Male near the red pool as the knockback from the Jealous male can knock the person in the pool out of it.


The red pool will spawn with Jealous Male but it takes a second of mating for the Foul Offsprings to pop out. You will want to to have the assigned player to run into the red pool as soon the Jealous Male spawns and not move from the pool until the Foul Offsprings are killed. You will get a message on screen when the assigned player runs to the pool – Player X has absorbed the Calming Pheromones!


Moving out of the pool will cause the player to get a debuff called Stale Pheromones that prevent them from entering red circle again to attract the Foul Offsprings. If the player does that before the Foul Offsprings are killed, the red circle will disappear and the Offsprings will run wild on the raid.


This player inside the pool will attract all the Foul Offsprings to him/her. They have about a 10 second grace window where they will hardly take any damage from the Foul Offsprings. This is a perfect time for your DPS to unload their AOEs. Once the Offsprings are dead, kill the Jealous Male and then go back on the boss.

Corrosive Slime

This is a DoT applied to a random raid member (there is no warning but there is an animation for it) throughout the raid. The animation, however, is too fast and easily missed to be reliable. Instead, everyone should periodically check their debuff window for this icon and ask for a cleanse. Note that on storymode there is no circle when this DoT is cleansed, that is a hardmode mechanic.




Additional Mechanics Strategy
Corrosive Slime Cleansing this DoT will now leave behind a yellow circle on the ground that damages anyone standing in it.
Twisted Spawn These mobs spawn at ~10% (176k HP) and will attack the raid. Tank them if you can but your efforts should be on killing the boss ASAP

In addition to all the mechanics described above for storymode, two new additional mechanics are in hardmode but one of them won’t kick in until the boss is ~10%. Keep the following in mind for hardmode

  • Enrage timer is 5:45
  • This means that you only need to assign 4 players on red pool duty as the 4th Jealous Male and red pool pops at 5:15.

Corrosive Slime (circle placing 101)

This is a DoT applied to a random raid member (there is no warning but there is an animation for it) throughout the raid. The animation, however, is too fast and easily missed to be reliable. Instead, everyone should periodically check their debuff window for this icon.


If you have this debuff icon on you, move to a good location that is

1) Not on top of the flowers

2) Not where the boss pops up after burrowing.

Once you have done that, either cleanse yourself or ask for a cleanse. Doing so will remove the debuff from you but leave a yellow circle on the ground. These yellow circles will damage anyone standing in them and persists for about a minute.

Here are some examples of ok circle placement and terrible circle placement.


The circle placement on the left isn’t perfect but it leaves room for melee to get on the boss and the assigned person to stand in the red pool. The circle placement on the right is fairly terrible as two players basically put circles around where the boss will burrow, making it harder for melee and tanks to get to the boss.

Twisted Spawn (boss burning 101)

Twisted Spawns are new adds in hardmode that spawns at around/after 5 minutes into the fight (contrary to popular belief, they are not spawned at the 10% mark and but spawns anywhere from 15-5% depending on your DPS. See screenshot below with Twisted Spawn spawning at 13%).


These things have 71k HP but you really shouldn’t be killing them. In addition to the Twist Spawns, you should also get the Jealous Male and the Foul Offspring to join in the fun. This is basically a max DPS burn phase, killing the boss down the final couple % before he spawns too many Twisted Spawns that wipes the raid.


By Dulfy

MMO guide writer and blogger. Currently playing and covering SWTOR, GW2, and TSW.

33 replies on “The Writhing Horror–Terror from Beyond boss guide”

/offtopic but I noticed debuff icons are showing seperately in your UI from buffs and other proc effects.
How do you do it ?

My guild is currently doing Storymode in almost full Campaign gear and are having a problem on some of the bosses. I’d recommend at least full Rakata

We mainly wiped on story mode due to learning mechanics. We finished the operation with 7-manning The Terror from Beyond. So campaign is not needed. I guess that good players with columi gear could do this operation.

We tried it for the first time on HM yesterday but after killing both the foul offspring and the jealous male, we sometimes got a second group of foul offspring when everybody was already back on the boss (and the red circle already disapeared)… Could this be a bug or does it have something to do with the tactics?

No, we usually get to max 7 stacks when the jealous male comes.. But when we got a second group, it came without a jealous male or warning, just a group of foul offspring without a red circle…

We had that problem too several times. In my opinion it is an additional hm mechanic that occurs, when the tank loses aggro. Also they seem to pretty much one-shoot the tank, you need to kill them off before they get to him.

[…] for TFB These are the videos for the first 3 bosses in Terror from Beyond learn the strat! The Writhing Horror–Terror from Beyond boss guide – Dulfy Ciphas, Heirad, and Kel’Sara–Terror from beyond Operation boss guides – Dulfy […]

Doing Hm, we doing rather well on first purple pool. when we get to second pool, the foul offspring spawn and the mate before the red pool and because there is no pool we are wiping. Is this bugged or we doing something wrong?

I believe that this is related to the Incubation debuff. The adds arrive when this debuff falls off someone. We have had the issue on the first pool if a DPS pulls aggro for a second and gets the debuff. If you’re having the issue with the second pool, are your tanks swapping back as soon as the Jealous Male goes down? Once the tanks swap, they can’t swap back until the next Jealous Male shows up.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.