Hello all,
Just trying to understand some of the aspects of a Mimic and how it attacks - especially in regards to the "adhesive."

It's the wording of how the adhesive is reabsorbed into it's body when it is no longer in "object" form...

Say a Mimic is disguised as a treasure chest.
A player walks up and touches it, and is now stuck to its stickiness (and becomes "grappled").
A) Assuming the Mimic gains surprise and gets to attack the stuck player first? Or is initiative rolled as soon as the player is grappled?

B) The mimic gains advantage to its attack roll against the grappled victim (for a bite attack). Once the bite attack happens, is the mimic no longer in object form at this point, which would mean the player is released as soon as the bite attack ends?

C) To add a little more to my confusion, in the description it says this, "The adhesive is absorbed when the mimic assumes its amorphous form and on parts the mimic uses to move itself." (looking at the illustration of the mimic in the MM, where it's like a treasure chest with teeth and large tongue)... Would that mean that like only PARTS of the mimic have the adhesive absorbed, while the parts that remain to look like the original object are still sticky? Like in the treasure chest example, the player could still be grappled it it continues to touch the top of the chest, but then say the internal mouth/tongue would not have the adhesive on it?

I guess basically I'm wondering can a mimic continue to grapple the player even after it's biting attack?

Thanks for any clarification.

So, historically, mimics retain their shape until it becomes unwise and unsafe. They extrude a pod to attack a stuck character, who unless restrained (both hands stuck, hands and a foot stuck, having been hit by a lot of pods) can kinda wiggle around to dodge the pods until they are restrained. Then they get drawn in for eating. 

they only suck in the adhesive and go amorphous when fleeing — even leaving behind a victim — because they are badly hurt, scared, etc.

as a side note, mimics also do doors, windows that seem to go outside (yes, even underground), furniture, foodstuffs, and in one of the few times where I was a player, they will do corpses or even gelatinous cubes. 

Thanks AeDorsay for the reply.
When you say "historically" do you mean more from a LORE point of view, or do you mean like from previous editions of D&D?
I'm asking about 5e, and I don't really see any mention about extruding a pod, or anything about having to have both hands and a foot be restrained.
I don't see anything in the rules either about getting rid of the adhesive only when fleeing.

Quote from Cyenobite >>

Thanks AeDorsay for the reply.
When you say "historically" do you mean more from a LORE point of view, or do you mean like from previous editions of D&D?
I'm asking about 5e, and I don't really see any mention about extruding a pod, or anything about having to have both hands and a foot be restrained.
I don't see anything in the rules either about getting rid of the adhesive only when fleeing.

I mean within the mechanics of the game, through all the editions, including 5e.

The mimic is one of the great core monsters -- so much so it is even featured in the upcoming movie -- and has pretty much been based on a shape changing blob ever since. Some of it is derived from the nature of the beast: This is a creature that has either really advanced tactile capacity, or it can see (to mimic things). It has to be able to move about and get into odd places in dungeons, and it has to find a place to set up a trap.

In reactions, most people will try to pry their hands free by placing a foot upon the thing they are stuck to. See my example of a door.

The mimic would not be an effective predator if it had no way of exuding the stickiness at will, and all things with this rough level of intelligence (not sapience or sentience, but still cunning) has *very* strong survival instinct and so it would naturally release the stuff in order to beat a hasty retreat; this is especially true for ambush predators.

I doubt they would drag a victim that is too strong or dangerous with them into their bolt holes -- hence the release.  

One of the challenges of DMing is to think about monsters are things that exist and draw inferences from more than just the written lore. If it wasn't, then the only way anyone would ever encounter a mimic is as a chest, and they would be missing out onf the ways in which a mimic is truly a scary creature.

Mimic was one of the first five monsters I ever used, way back in 1980.  

Quote from Cyenobite >>

Thanks AeDorsay for the reply.
When you say "historically" do you mean more from a LORE point of view, or do you mean like from previous editions of D&D?
I'm asking about 5e, and I don't really see any mention about extruding a pod, or anything about having to have both hands and a foot be restrained.
I don't see anything in the rules either about getting rid of the adhesive only when fleeing.

 The extruded pod that AEDorsay mentioned is their pseudopod melee attack, I believe. 

A) there is no “surprise” round in 5E so I would say roll initiative when a player gets stuck, but would consider them surprised so they cannot act on the first round. 

Surprise

A band of adventurers sneaks up on a bandit camp, springing from the trees to attack them. A gelatinous cube glides down a dungeon passage, unnoticed by the adventurers until the cube engulfs one of them. In these situations, one side of the battle gains surprise over the other.

The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn't notice a threat is surprised at the start of the encounter.

If you're surprised, you can't move or take an action on your first turn of the combat, and you can't take a reaction until that turn ends. A member of a group can be surprised even if the other members aren't.

B) the advantage is for any of the mimics attacks on the grappled victim. And they remain in the form (chest shape for example) until they decide to change to their true amorphous form, which AEDorsay described like when they flee. The player has to beat the DC 13 with a Strength (athletics) or Dexterity (acrobatics) check to free themselves. They don’t automatically release unless the mimic actually releases them. 

C) the parts that are not sticky, in my opinion, could be the bottom of the chest, unless it is anchoring itself to the floor to hold a victim. Or any other area the DM decides. So all parts of the chest including inside the mouth and on tongue would be sticky unless the mimic wants to absorb it to release something. 

Quote from ThriKreenWarrior >>

C) the parts that are not sticky, in my opinion, could be the bottom of the chest, unless it is anchoring itself to the floor to hold a victim. Or any other area the DM decides. So all parts of the chest including inside the mouth and on tongue would be sticky unless the mimic wants to absorb it to release something. 

 ^ This is how I've always done it. The Mimic will maintain its hold, to continue to have advantage on the target.

Sadly, it's typically not ever wise for the mimic, because it can truly only ever focus on one target this way. So unless the Rogue/Bard/whoever has scouted ahead and foolishly touched a door, chest, spear, whatever - that the mimic is impersonating - the rest of the party pounding on the mimic typically goes poorly for the mimic. So I typically rule it that anything that touches the mimic (fighter's sword, for example) can also become stuck because of this line: The mimic adheres to anything that touches it.

Yes, yes to all.

mimics are creatures that are frustrating but susceptible to range and magic attacks.

A Mimic living in an environment with monsters who have at least an INT of 4 might also have noticed that the Mimic is an effective ambush predator. So those monsters might pay special attention to the Mimic's location and "help it out", e.g. try to kill non-restrained party members who happen to be carrying valuables around or who smell/look tasty.  It's your call as the DM how complex or simple you want the dungeon encounter to be.