The Underrot Mythic+ Dungeon Guide

Instance Breakdown

Instance Timer: 33 minutes
Wowhead Link: Link



We're in and we have a choice right away. We can clear the Ticks to the left or the Maggot to the right. The Ticks are generally the better choice outside of Bursting where the explosion damage combined with five stacks can be difficult to survive. If you do clear the Fetid Maggot to the right then watch for its cone AoE. Don't stand in the direction of its mouth maw... thing. Next, clear the Blood Matron. It'll leap to random players and cast a heavy frontal cone AoE. You MUST avoid it.
Clear the pack in the middle and then take a look down both the left and right pathways. One will include a Double Matron that will make our lives very difficult. We're going to go down whichever path doesn't have that. Clear the patrol from your chosen path.
The Befouled Spirit is a sanity-breaker so we're going to Shroud or Invis pot past it. Stick hard right as you walk through. You really don't want to clear this mob. If you're low on gold I'll pay for your invis pot.
Kill the boss and head down the path to the right.
Grab these one at a time. For the Maggot / Tick pack you'll want to consider using a long CC on the Maggot and pulling the pack back toward the boss. Its frontal cone is particularly dangerous when coupled with the unavoidable Tick explosion damage.

Key Interrupt or dispel (disease): Decaying Mind (Diseased Lasher, 30s stun)
Pull through every pack in Cragmaw's room, taking care to avoid the boss until they're all dead. They mostly pull in 1-2 mob packs so grab as many as you can take at once. Usually 3-4 mobs at a time. The Bloodswarmers will fixate a random target and attempt to eat them. Kite, CC, and kill them first. They also cast a heavy AoE called Sonic Screech that silences anyone casting. Interrupt it.
We're clearing every mob in Cragmaws room. It makes the boss much easier.
The Reanimated Guardians will cast big shields on themselves. Purge them or use AoE CC to burn them down.

Key Interrupt or Soothe: Wicked Frenzy (Fallen Deathspeaker, +100% haste)
The red cloud will turn into a giant worm with a must-interrupt spell called Death Bolt. They spam cast it. You brought good interrupts though, right?
Have your interrupters roaring to go against the double defiler pack. Withering curse must be interrupted.

Key Interrupt: Withering Curse (Bloodsworn Defiler, +dmg taken, -dmg done). They'll also summon a little totem that you need to stay away from. It stuns within 6 yards. Don't bother killing it.
Skip the patrol to the left. Skip the Corruptor in front of you by hugging right and then invis pot or shroud through to the pack in the middle. This isn't a huge value skip but we're up on trash percentage and they're slow kills.
We're going to sneak through the middle here and avoid the mobs to the left. You might need to wait for the Corrupter to patrol away.
The instance ends with a double Corrupter pack. They will face a random player and cast Maddening Gaze - a line AoE that'll fear you into other packs. Dodge it. Dodge the various tentacles too. This should get you to 100% but if you missed something then find another worm or two behind you. Killing them will trigger your final Reaping and you'll want to jump down the pipe and fight them in the bosses room. It'll give you more room to move.

Method Dungeon Tools Strings

Classic Path (pictured above)



  • Elder Leaxa

    Cults man. God damn cults.

    Dungeon Journal+

    Blood Bolt   Magic Damage   Interruptible 

    Creeping Rot   Magic Damage   Dodgeable

    Sanguine Feast   Magic Damage   Dodgeable   Fatal


    You should know

    • This is an easy fight if you have strong group DPS and the ability to step back from the boss during Sanguine Feast.
    • Creeping Rot is fired in a random players direction. You have plenty of time to dodge it but if you don’t it’ll one shot you.
    • When a Blood Effigy spawns focus it down first, unless the boss is sub ~20% health.


  • Cragmaw the Infested

    Gross, and yet one of my favorite mounts.

    Dungeon Journal+

    Indigestion   Magic Damage (Frontal Cone) 

    Charge   Physical Damage   Dodgeable

    Tantrum (Cast every 45s)   Physical Damage   Avoidance 


    You should know

    • Tank Cragmaw toward the side of the room. Have your DPS and healer stand to the left and right of him with their backs against the wall. When he Charges at one of them you want to minimize the distance he travels. This increases DPS time and reduces the number of Larvae you have to crush.
    • Tank: Indigestion will always fire in your direction but is 100% dodgeable. Once he starts the cast simply sidestep then return to where you were standing.
    • During Tantrum your entire party will need to spread out and squash Larvae. Assign each of your party members to a quadrant. Your healer might struggle to get many depending on class since this is an ultra high damage phase. Pop your defensive cooldowns here. You won’t take damage anywhere else in the fight if you play it properly.


  • Sporecaller Zancha

    This is where your healer finds out how well the group can do mechanics.

    Dungeon Journal+

    Decaying Spores   Magic Damage   Debuff (DoT, Stacks)

    Festering Harvest   Magic Damage   Avoidance 

    Shockwave   Physical Damage (Frontal Cone)   Dodgeable

    Upheaval   Physical Damage   Dodgeable


    You should know

    • This instance is actually quite interesting in that most of the bosses are quite easy if you do the mechanics properly and unforgivably difficult if you don’t.
    • For this fight the keys are to clear as many mushrooms as possible with the bosses mechanics. You don’t need any tricky cloak clears or immunities. You just need to use the tools given to you to their maximum potential.
    • Upheaval: Targets two players at once. Will clear any mushrooms it hits. You’ll want to run from it so it doesn’t actually hit you since it does very heavy damage.
    • Shockwave: Targeted at the tank only. Stand such that there’s a giant pile of mushrooms behind you. Side step it as the cast completes.
    • Healer: You’re playing catch up here. You’re going to save your group from any mistakes. Heal anyone that stands in a shroom and save your big healing cooldowns for if any are missed when Festering Harvest is cast.
    • It’s better to run into any remaining mushrooms during the Harvest cast instead of letting the boss blow them up.


  • Unbound Abomination

    Kind of like Argus but with blood and fungus.

    Dungeon Journal+

    Putrid Blood   Magic Damage   Debuff (Magic, DoT, Stacks)

    Vile Expulsion   Magic Damage (Cone) 

    Blood Barrier


    You should know

    • Alright, pretend the Vile Expulsion is a big Sweeping Scythe. You’re going to stay reasonably grouped and then when the cast starts you’ll rotate to the left or right. This is honestly the only ultra dangerous mechanic in the fight.
    • The boss doesn’t actually take damage from your attacks. Instead they cause him to drop little blood adds. Killing those will damage the boss and killing six will end the fight. Fortunately Titan Keeper Hezrel followed us all the way here without doing anything and finally joins in. He’ll occasionally smite one for you and because of this you can keep most of your focus on the boss himself.
    • The Spores will slowly travel toward you. If they hit you they’ll straight up kill you. Hit any that get close. They have no health.
    • Healer: Unbound Abomination is full of slow heavy ticking damage. The group will clear all stacks of the debuff whenever Cleansing Light drops (the big yellow circle) but I’d recommend individually dispelling at 2 stacks to help control the incoming damage. It’s a more efficient global cooldown than a heal.

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