Better Mimic

Mimics take the form of ordinary chests in the world, with the same model, size and rotation as the real thing. Players cannot tell them apart until a mimic is disturbed, and an aggressive one moves in on a player who is looking toward it. Mimics spawn naturally in the world and can also be placed with spawn eggs, which suits testing or building encounters on purpose.

Two behaviors are included. Aggressive mimics sneak up on players and attack with leap strikes and a tongue attack, with smooth animations and particle effects. Passive mimics stay harmless until a player tries to open them. Their AI follows the player's line of sight, so the mobs react when a player looks at them. Defeated mimics drop valuable loot, which gives the treasure chest a second meaning.

Servers that run it need every player to install it too. It is published for Fabric only, for seven game versions 1.20 – 1.20.6, with 1.0.0 for 1.20.6 as the latest file, released under the MIT License. Better Mimic is not open source in the sense of a public repository, but the license allows free use, modification and distribution.