A larger, similar species to the Trapdoor Mimic, the Tile Mimic possesses a cruel and devious mind. As such, it likes to play with its food. The monstrosity can suppress its adhesive ability and allows the prey to filter in and inspect whatever random ‘puzzle’ its outer shell presents. From there, it plays the part of an acid spray trap, shooting caustic fluids now and again while manifesting pressure plates and cogs. Then, once it’s grown bored as a cat does with a mouse, the devouring begins.

Tile Mimic

Large monstrosity (shapechanger), neutral

Armor Class 15 (natural armor)

Hit Points 93 (11d10 + 33)

Speed 10ft

Str 18 Dex 7 Con 17 Int 10 Wis 13 Cha 8

Skills Insight +3, Sleight of Hand +0, Stealth +2

Damage Immunities acid

Condition Immunities prone

Sensesdarkvision 60 ft., passive Perception 11

Languages -

Challenge 4 (1,100 XP)

Shapechanger.

The tile mimic can use its action to polymorph into a tile floor trap or back into its true, amorphous form. Its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Adhesive (Object Form Only).

The tile mimic adheres to anything that touches it. A Huge or smaller creature adhered to the mimic is also grappled by it (escape DC 14). Ability checks made to escape this grapple have disadvantage. The tile mimic can activate or deactivate this ability as a bonus action.

False Appearance.

While the tile mimic remains motionless, it is indistinguishable from an ordinary tile floor.

Grappler.

The mimic has advantage on attack rolls against any creature grappled by it.

Trap Mimicry (Object Form Only).

The tile mimic manifests mechanisms just under its 'skin' that appear to be parts of a trap such as cogs, pressure plates, and springs. A successful DC 15 Dexterity (Thieves Tools) skill check 'disarms' the trap. If a creature succeeds on this check by 5 or more, they realize that the trap mechanisms are a spoof of an actual trap

Actions

Multiattack.

The tile mimic makes three psuedopod attacks.

Pseudopod.

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.

Bite.

Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) piercing damage plus 9 (2d8) acid damage.

Reactions

Sprung Trap (Object Form Only).

Any time a creature steps on the tile mimic it may use its reaction to spray it with acid. The creature must succeed on a DC 14 Dexterity save or take 13 (3d8) acid damage. This appears to be a trap activating.