The 20ft movement speed is a real problem for this monster. If the party has enough room to retreat, even low level parties can take this down without taking any damage. Consider positioning at the start of the encounter carefully.

Quote from Glenn >>

Multiattack. The shambling mound makes two slam attacks. If both attacks hit a Medium or smaller target, the target is grappled (escape DC 14), and the shambling mound uses its Engulf on it.

Is the Engulf action meant to occur on the same turn as the two Slam attacks? The Multiattack wording seems to imply this, but with Engulf listed as a separate action I'm not so sure.

 Was wondering about this, as well.  Anybody have thoughts on this question?  Thanks!

Quote from Hopkins >>

Quote from Glenn >>

Multiattack. The shambling mound makes two slam attacks. If both attacks hit a Medium or smaller target, the target is grappled (escape DC 14), and the shambling mound uses its Engulf on it.

Is the Engulf action meant to occur on the same turn as the two Slam attacks? The Multiattack wording seems to imply this, but with Engulf listed as a separate action I'm not so sure.

 Was wondering about this, as well.  Anybody have thoughts on this question?  Thanks!

 It's happening immediately after two hits connect, as I see it. Maybe it's listed as a separate action if Shambling Mound wants to grapple and later engulf the target without slamming it? DM can always choose to grapple instead of making Multiattack.

this seems to strong for the death house cr five for like a party of 4 level  2s

Quote from Dwayne >>

I just bought the miniature for this monster cause it was so cool and would love to run it for my daughters 3 person level 1 party instead of all the normal 1st level suspects < humanoid monsters but it would absolutely destroy them. Any ideas on scaling this back to be a somewhat scary and challenging monster for a beginner group? I was thinking that they could run into smaller " chunks" of the mound throughout the adventure then at the end after fighting all the little guys they see it come together and merge into one large mound ala a Transformers for the final confrontation. Thoughts?

 maybe you could have it trapped in some kind of ravine, and just before the PCs destroy it, it can escape and slither away, and comes back at a higher level.

 this is good for a swamp

I used this as a boss creature for my players (Level 4 party) and it was an awesome fight. 

I Changed it to be a creature made out of mold though^^

because they're meant to run away from it.

Quote from Qwerty3 >>

because they're meant to run away from it.

 The gate closes behind them in it

My party was exploring a sunken ship, and we found one of these made of seaweed. The artificer got swallowed up by it, and dropped to 0 hp. I very nearly hit it with lightning damage because I had no clue what it was, but I’m pretty good at reading the DMs poker face, and I saw him grinning when I was about to do it. We killed it and saved the artificer, but it was a pretty hard fight for our level 4 party.

Hehe olmost kills level 4 party vit 5 members

What happens to an engulfed creature if the mound is to die? Are they free or still engulfed.

Quote from OKMindFlayer1000 >>

Quote from Qwerty3 >>

because they're meant to run away from it.

 The gate closes behind them in it

The wooden wheel that opens the gate is on the wall inside the room, next to the gate. In addition to that, there's a secret door that allows passage to/from area 36. There's multiple ways for the party to escape, especially with the mound's slow 20ft speed.

Quote from ElyeAlexander >>

Quote from Rynegade >>

It seems like an Engulfed creature can not be removed with Rules as Written, compared to language used for Gelatinous Ooze.

 Yes, I think there's an oversight/omission in the rules text here. I'd suggest using the Gelatinous Cube's rules for escaping from an Engulfing shambling mound (though maybe with a higher DC).

 
I think it's just a matter of escaping the mound's grapple, using the general rules already in place for doing so.  The escape DC *is* given in the stat block.

The cube mentions a specific means of escape because it's an ad-hoc mechanic, rather than being based on being grappled, an already-existing mechanic.

 Should Abi-Dalzim’s Horrid Wilting make it weak to fire?
Because it is only resistant to fire because it is moist.

yeah same here, never ever got the engulf off. and we managed to kill it on the alter!!

Quote from FinalKingdomHearts >>

 Should Abi-Dalzim’s Horrid Wilting make it weak to fire?
Because it is only resistant to fire because it is moist.

 

 probably up to the dm on that but in my game id say so

Quote from TheBuffWhiteKnight >>

Hahaha, it took me way too long to realise that there was a person in the picture.

 omg i didnt even see that until you pointed it out whoa

Our lvl 2 party (4 ppl) managed to kill it in CoS. Though one of us died and two were laying unconscious, while the last one standing simply didn't miss even one shot and rolled incredibly good damage + kited the hell out of that ugly thing, since it's quite slow, which probably is its only weakness.

It's possible to kill it with lvl2 party, but quite hard and luck-dependant.

AAAH