I brought up evolution as a way to explain the idea that even without magic it’s possible for there to not be any motion when a creature is breathing. There are also worlds where a mimic could be a normal animal, so that’s good there too. You, hilariously, are aaking if evolution even applies to aberations while being dead-set on them breathing, as if that isn’t a comically easy thing to hand-wave away if we’re saying the creature is a proper, built-for-purpose monster. The book says “motionless” and “indistinguishable”. Those words mean “_without_ motion” and “with _nothing_ to [visually] distinguish it from the object it is trying to imitate”. There is no breathing motion because then it would not be motionless and there is nothing to tell it apart. Both of those are ok in a game context because there other ways to discover the monster. We aren’t talking about your subjective opinion and your original comment was an “um actually” in relation to someone else’s so if you want to know why you’re having this conversation it’s because _you_ started it.

I copy-pasted from the 2014 entry.

I'm going ahead and hit "doubt" on that statement as I looked at my 2014 Monster Manual before writing my previous message and the word "nearly" is absent in that description.

I don't know what to tell you. I went to 5etools, looked at the 2014 lore, and directly copy-pasted that exact quote. You can check yourself. If I wrote it, I'd have spelt unrecognisable with an s instead of a z. Maybe it got errata'd at some point?

Ok, so I'm sorry about my previous tone, it seems that the mimic article, on 5etools and the SRD website, is the source of our confusion and disagreement: each time the description appears twice, first without the word "nearly" (under "False Appearance") then once with it. That 2nd description, under "Imitative Predators", does not appear in the Monster Manual. I could not check what D&D Beyond says because I do not have access to its contents.

Note that a feature applying while motionless doesn't mean it is motionless. And based on the rules, no, there are no other ways to distinguish the monster if it is motionless. Look at the comment above mine. THAT was an um actually. OP described a perception check for a mimic, the comment I replied to said "um actually, there wouldn't be a perception check", and I replied with why there would be. Why are you making me the villain for defending the post?

Motionless and _indistinguishable_. Chests and crates don’t breathe and you’d be able to _distinguish_ the two very easily based on that. An _investigation_ check could work, or maybe a straight intelligence roll. Paying attention to the description of the room, too, and passive investigation is a real thing as well. I’ve already explained at least twice that you can use those ways to figure out that something isn’t where you left it or otherwise seems out of place. You can absolutely still find it using mechanisms that don’t require getting chomped. You’re just wrong. It’s fine, it happens, but the plain english is making it reeeeeally hard for me to understand how on earth you could be confused here.

Cool. Mimics breathe. Roll perception to see if you spot the motion of the mimic breathing.

Indistinguishable *if motionless*. If not motionless, distinguishable. You seem to be assuming that because it CAN be indistinguishable, it IS indistinguishable, and thus cannot be moving. Meanwhile, Dark Souls has mimics that breathe, and they work perfectly fine. Easy to get caught out, but definitely possible to spot if you're careful. Yes, you have explained twice how you can distinguish a creature that cannot be distinguished. And I've pointed out how paradoxical that is. Like, are you okay? Genuinely, I'm getting concerned for you.

Didn't know that, actually. How's their poison resistance? Can they hold their breath? Does D&D have spells that let you do things like deoxygenate a room?

Well, is there some true sight or something that let's you see a mimic?