The Dread Guard’s Corrupted Mask is a rare Headgear in SWTOR that provides a unique Buff when equipped as Gear. To earn a Corrupted Mask you must kill Dreadtooth, the Worldboss on Section X.

What makes the Dread Guard’s Corrupted Mask unique is that it is a hornless version of the Dread Master’s Masks and it is the only Dread Master helmet that you can obtain without having to play a Nightmare difficulty Operation (raid).

A minimum group size of 4 with 1 Tank and 1 Healer is suggested to take on Dreadtooth. While he is quite easy to kill, he has a 7 minute enrage timer and a LOT of Hitpoints.
There is no way to guarantee that you will be rewarded the Corrupted Mask, as it is given randomly to a groupmember that helped kill Dreadtooth. Once looted the item can be temporarily Traded to any group members. Once the Mask has been used in the inventory it will open as a Bound version, meaning it can no longer be traded to other members of your Group.

If you wish to farm the Dread Guard’s Corrupted Mask with a group. I suggest killing Dreadtooth at 1 stack and alternating between the PvP and PvE instance of the planet. As this will allow you to get more kills while waiting for Dreadtooth to Respawn.

What makes Dreadtooth a special Worldboss is that players can increase the difficulty of Dreadtooth manually by using a Dreadful Essence item on the Boss. Each stack increases Dreadtooth’s Health and Damage.

At 1-2 Stacks, Dreadtooth drops 1 Dread Mask as loot upon death.
At 3-10 Stacks, Dreadtooth drops 2 Dread Masks as loot upon death.

If you have a group size of 8 or more, I suggest farming Dreadtooth at 3 Stacks for 2 Mask drops per kill instead of 1 Mask at 1 Stack. As long as you have 1 Tank and 2 Healers you should be fine.