The Mimic is one of the classic trap monsters from D&D. In the AD&D Monster Manual, they are described as capable of taking on the appearance of any type of inanimate object made of wood or stone, but they are sterotypically portrayed as medieval travel chests.
Another take on the Mimic that I've always rather liked comes from Dragon Quest, but these Mimics are more akin to tsukumogami (possessed/animated objects) than shapeshifting D&D Mimics.
Mimics are actually fairly scarce in miniature form. Ral Partha made a set of three different Mimics (chest, barrel, bed) for their AD&D Monsters line. More recently, Otherworld has produced some Mimics in metal, while resin Mimics come with the Super Dungeon Explore boardgame.
The Otherworld Mimics (left) are of the more traditional variety, while the SDE Mimics are of the DQ type (right). Both of them are pretty big for chests, but given that Mimics are supposed to occupy a volume of 150 cubic feet, they are pretty close to 1/72 scale (if not undersized).
Another creature related to the DQ type of Mimic is the Pot Devil (壺魔人 or つぼまじん) which attacks by swallowing anyone looking inside of it. I believe that they may have first appeared in DQ, but the only image I could find is from Final Fantasy where it is known as a Magic Pot.
These are dollhouse miniatures that I picked up from eBay, some of which I plan on using as Pot Devils. The first five are ceramic, while the last one is metal with a separate lid.
The typical Pot Devils seems to be colored in earth tones, and may often have an unglazed finish, so I'll probably add some surface details to the pots, and refinish with a rougher surface.
The last two types of monsters are also closer to being animated objects than actual Mimics, but it felt appropriate to include them in this post.
First we have the Maneating Casket from Castlevania and the Deathgrasp Sarcophagus from one of the newer incarnations of D&D. The Casket hops along, chasing it victim with the intent of eating them whole. I believe the Sarcophagus behaves similarly, though it merely imprisons its victims rather than eats them.
The Maneating Casket on the left is built of basswood. I'm going to see if I can get moulding and a cross made of strip styrene glued to the wood. If not, I'll have to buy some thicker plastic card to remake the casket. On the right is the Deathgrasp Sarcophagus (Demonweb #10) from the D&D CMG.
Last is the Creeping Coin, taken from Sir-Tech's Wizardry. These were animated piles of coins with a "breath attack" consisting of firing coins at the party. They were weak, and did almost no damage, but they could call for other wandering monsters (nothing more alluring to wandering monsters than the sound of jingling gold coins), which made them very dangerous.
To make the coins I sliced sections from a 0.02" plastic rod, glued them to a metal washer, and painted them gold. Next time I'll start by painting the rod gold so I won't have to worry about painting the edges of the coins.