Imagine if you will, you're an adventurer and you think you've seen everything and BOO! You've been ambushed by a jar mimic! These venomous and monstrous pseudolamias have a squishy, spongy body that they can cram into even the tiniest of spaces where they lay in wait and leap out at anything that crosses their paths. While they used to prey on wild animals they've adapted to instead target adventurers, not to eat but rather to rob blind. You pass where one is hiding and they leap out at you, knock you to the ground, grab whatever they can of value, and have slithered off and squeezed through a tiny opening to escape before you can even react. Unlike normal mimics they eat normal food, but will steal gold and valuables as well either to wear (the shiny clinky things make their scares more dramatic) or to turn around and trade to others for food. Always be on guard since they can hide in almost anything, with old jars and urns simply being their preferred hiding places due to greedy adventurers liking to break them open in search of valuables :D

They love Nightmare Night more than anything else and are known to jump trick-or-treaters to steal their candy :P