Shambler

Shambler =

Shambler Tentacle = "The space between worlds is no place for mortal men."

- The Ancestor

A predatory nightmare summoned from the darkest recesses of the unknown, the Shambler is an Eldritch miniboss that lurks in blackest pitch, dropping Ancestral trinkets when killed. When traveling with your torchlight at 0, the Shambler may appear, replacing any hallway fight (1% chance on Apprentice, 8% on Veteran, 12% Champion), or when a Torch is used on a Shambler's Altar (which will also set the light to 0). Every turn, it will attempt to spawn two Shambler Tentacles, fairly weak enemies that give themselves an enormous buff with every attack, causing it to grow stronger and stronger. Even if a Tentacle is killed, the Shambler will just create a new one, replacing ones that were killed.

Behavior
The Shambler fight will always be at 0 torchlight, with all the buffs and debuffs associated, and the light cannot be increased with torches or skills while the Shambler is still alive. The party will always be surprised when the battle starts, disrupting party formation. If summoned but then ran away from, the Shambler will appear again as the next encounter. Don't summon it unless the party is prepared to kill it.

Due to a very low speed, it will most likely act last, using either Obdurous Advancement or Undulating Withdrawal and summoning 2 Shambler Tentacles. Unlike the Shambler itself, the Tentacles have a very high speed; they are very likely to take actions before the party, applying an extremely strong buff to themselves. If one or both of the Tentacles are killed, the Shambler may attempt to re-summon them the next time it acts by. If at least one is left alive, the Shambler has a chance to use Stentorious Lament, which will shuffle your party's formation again in addition to causing stress.

Strategy
The Shambler is easily more dangerous than most bosses, meaning it's usually better to avoid fighting it. If you decide to spawn it from an altar, you should probably wait until the quest is finished, as you'll likely be in no condition to continue afterwards.

The Shambler is equally vulnerable to bleeds and blights, but at only 1 action per round, they will not progress very quickly. They might still be ideal to use though since this demon has 33% prot. This is on top of fair amount of dodge. Fortunately though, it has a slow speed, so your party is almost guaranteed to go first. Debuffs may be useful to reduce its prot or dodge.

Much of the danger in fighting the Shambler is that it's always in darkness. This inverts valuable perks and trinkets, expecting the opposite of what you probably have. If you want to equip specifically for the Shambler, consider moon trinkets as they work in darkness. If you're fortunate enough to have the idol trinket (from killing the Shambler, no less), it's effective for the fight. Hero rings can also grant +25% virtue, and aren't unique. A party with 1 on every hero, combined with any moon or similar trinkets, would be highly effective against the Shambler. Since you'll most likely hit 100 stress on several heroes, you should either be prepared to counter the stress, or increase virtue.

That is, unless you can end this fight quickly. A well equipped party with Level 1 and 2 Heroes that synergize to deal good damage can work their way through the Shambler‘s hit points pretty fast.

As the Shambler also likes to shuffle your party, heroes with move skills will be more effective. A full party shuffle is guaranteed to occur at the start of the fight, and bound to happen again as the fight goes on. To reduce the impact of the initial shuffle, reorder your party yourself so that frontline fighters are in the back and back row fighters in the front. That way you have a fair chance to be shuffled pretty much back into your ideal fighting line-up.

The Shambler‘s main strategy is to summon 2 tentacles, which have high speed, and grow stronger every time they land an attack. They power up quickly, and in a few rounds, will be frightening in stats. Keeping these tentacles cleared as much as possible, is recommended to keep them from powering up. Stuns can also work by causing them to lose an attack. If they can't attack, they do not gain any power a round. It's also important to note that the tentacles do not die when the Shambler does.

To deal with the tentacles, multiple target skills are effective. The Abomination in particular can not only slice both tentacles every round, but power himself up in the process. After a few rounds, he'll become fantastic at keeping them cleared. If you have the Crusader or Leper, they might be able to suffice. The Highwayman can also triple shot, hitting the boss with its tentacles.

Harming the Shambler is hard due to its stats. If you have armor piercing, make use of it on the Shambler. If not, you may find dot stacking to become your best source of damage. Another strategy is using riposte. Since every Shambler skill targets the entire party, it will thus trigger every riposte, every round, and while the Shambler dashes itself to death on your counterattacks, you can focus on keeping the tentacles under control. This makes the Highwayman and Man At Arms quite effective for the fight. The Occultist gains a damage boost during the fight, making his dagger stab particularly powerful. The Jester is also effective with his bleed strikes and ability to reduce stress.

Another strategy is to maximize your damage output by marking the Shambler, there's plenty of prot+dodge to remove, on top of powering up other skills. Then use an Arbalest, Hound Master and/or Highwayman to kill the Shambler - all of them are able to attack positions 3+4 where the Shambler will reside most of the battle and benefit greatly from the Mark. A Leper or Crusader can kill the tentacles and a Healer holds the party together.

Finally, make sure you have bandages and antivenoms to deal with the dots your party will no doubt receive. Using items to remove these will conserve your turns. Holy waters can increase resist, but will not remove anything once applied.

I ran Hellion (Iron swan or wild hack target shambler) Houndmaster (Mark and bleed) Highway man (Grapeshot tentacles) Vestal (Team Healing) camping before activating the altar and buffing my highway man with trinkets also to oneshot the tentacles. The tentacles could also easily be combated without the buffs using a combination of grapeshot and hound's harry so long as the highway man's first move is seeking shot for the accuracy buff.

Ancestral Trinkets
The main reason for hunting down this monstrous creature is because it carries 5 unique Ancestral-rarity trinkets. Every time the Shambler is slain it will drop 1 of the 5 trinkets below. Since all ancestor trinkets are unique, once you have all 5 of these, it will start dropping gems instead. The trinkets are dropped regardless of the Shambler's difficulty level, meaning there is almost no reason to go hunting for a Champion-level Shambler.

Abilities
Since the Shambler fight is starts at 0 torchlight and cannot be illuminated during the battle, enemy abilities are buffed +25% DMG, +5% CRIT, +12.5 ACC). The tables below show the unbuffed numbers.

Apprentice =

Shambler Tentacle
Veteran =

Shambler Tentacle
Champion =

Shambler Tentacle
* Summoning will occur whether the ability lands or not.

Wandering Bosses

 * The Collector
 * The Fanatic
 * Thing from the Stars

Trivia

 * In the early access and the original release the Shambler left a normal Corpse after it was killed instead of a large one, despite it taking up 2 Ranks during a fight.
 * As evidenced by its corpse, the Shambler has purple blood.
 * The Shambler features in two Journals that can be found in the game. The first, "Journal of Darius, Highwayman", ends with Darius' party being ambushed and slaughtered by a Shambler. The other one, "The Blackest of Fates", documents the fate of a party whose occultist, "thrice damned Mizir", activated a Shambler Altar and unleashed a Shambler upon everyone.
 * As of the Inhuman Bondage update, the Shambler will physically drag the party into another dimension. The area resembles a violet galaxy and functions the same as Pitch Black.
 * The name "Shambler" likely comes from the "Dimensional Shambler", one of HP Lovecraft's creations. The Dimensional Shambler is a creature that comes from another dimension and attacks its prey by using a form of hypnosis to make the victim believe they've been dragged into another plane of existence. However the appearance of the Shambler does not match the description given of the Dimensional Shamblers, as they are mostly humanoid. Rather the Shambler's appearance closely resembles the description given of the Shoggoth, said to be "vaster than any subway train— a shapeless congeries of protoplasmic bubbles, faintly self-luminous, and with myriads of temporary eyes forming and un-forming. "
 * Another reference to Lovecraft is when the narrator calls it a "Star-Spawned horror." In Lovecraft's work the Star Spawn are another name for the Cthulhi, which are spawn of the Great Old One Cthulhu, one of the central beings of Lovecraft's mythos.