Mimic

Version 0.28: This article may not be up to date for the latest stable release of Crawl.

Mimics are mischievous entities which harmlessly toy with passing adventurers. They disguise themselves as shops, and in certain areas, items - most notably the rune of Zot in Vaults:5. However, once you come within a one-tile radius of them, they will "vanish and cackle," disappearing from the game forever. Mimics are most often harmless, though a mimic rune may lead to hazardous situations

To clarify, mimics are not monsters, and cannot be killed in any way.

History

• Prior to 0.28, portal levels could be a mimic.
• Prior to 0.17, mimics could randomly generate anywhere as an item or many dungeon features, most importantly staircases.

more dungeon features mimics could generate randomly, most importantly staircase could be a mimic.

• Prior to 0.16, mimics were a category of monster which would resemble items or dungeon features, only to attack once the player got close enough. They came in standard, inept, and ravenous varieties.
• Prior to 0.15, mimics could disguise themselves as doors, statues, fountains, or hatches.