Mimic

The Mimic is a rare enemy that mimics an ammo chest. After the Desert, there's a 1/11 chance that an Ammo Chest will instead spawn as a Mimic. Once a Mimic is killed, it will drop two mini pickups: Mini Ammo Chests and/or Mini Medkits and 6 Rads.

There are a few ways to find out whether a chest is a Mimic or not:
 * It won't have the "shine" effect that regular chests have.
 * It will play an animation showing its tongue every once in a while.
 * It makes a slurping sound that can be heard if your character is close enough.
 * It plays the attack animation when touching another enemy.
 * Projectiles fired by the player will impact it.
 * You will take damage if you touch it.
 * If a Mimic is encountered in the Oasis a bubble will apear around it.