How many hit dice does a mimic need to mimic a 20'x20'x10' building?

[ParagonDireRaccoon]

How many hit dice does a mimic need to mimic a 20'x20'x10' building?

[TarkXT]

Depends on who you ask. That's my take.

[Rynjin]

Not sure it has anything to do with HD.

A Mimic has a volume of 150 cubic feet. It can't take a form bigger than that.

You're looking at 4000 cubic feet.

"Legends and tales speak of mimics of much greater sizes, with the ability to assume the form of houses, ships, or entire dungeon complexes that they festoon with treasure (both real and false) to lure unsuspecting food within."

But I can't find any rules for them.

There's a CR 8 (Failed Apotheosis) Mimic with 1200, that's as big as I can find.

[ParagonDireRaccoon]

Thanks! I could estimate what size category the mimic would need to be, and use monster advancement rules (which include increasing size category).

[Petty Alchemy]

What about stacking Mimics brick by mimic-brick?

[Zhayne]

You could just go 'this mimic is this big' and be done with it.

[ParagonDireRaccoon]

TarkXT wrote:

Depends on who you ask. That's my take.

The cottage that moves works perfectly for what I have in mind.

[Quandary]

Zhayne wrote:

You could just go 'this mimic is this big' and be done with it.

Yup. If the size of it wouldn't really affect it's difficulty (if anything, more characters can threaten a larger creature), then there's no reason to increase it's CR, and so you shouldn't need to increase the HD, either.

[ParagonDireRaccoon]

It's not going to be a threat to PCs or NPCs unless attacked- it's a mimic taking the form of an unused building that minds its own business. I like having it around CR 11, if it becomes collateral damage to an area effect spell both sides would be in trouble.

[TarkXT]

Keep in mind Big Mother is CR6.

What makes it CR11 is the 5 other mimics inside adn the expectation that people would encounter it while "inside" the cottage. In those circumstances it is a very very hard fight indeed.

[Lamontius]

this is like a terrible version of how many angels can dance on the head of a pin

[ParagonDireRaccoon]

TarkXT wrote:

Keep in mind Big Mother is CR6.

What makes it CR11 is the 5 other mimics inside adn the expectation that people would encounter it while "inside" the cottage. In those circumstances it is a very very hard fight indeed.

That still works, I can reduce the CR by one if they provoke the mimics with a careless fireball rather than going inside the building. Sometimes players are a little reckless about collateral damage, so I'm thinking of mimics as an abandoned building in a part of town where PCs are likely to be ambushed by NPCs.