D&D knows Mimics and their relatives, the Lurker and Trapper. They are aberrations that mimicpun intended the floor and ceiling and have been used in conjunction with a stunjelly for years to make a room that lusts for adventurers to eat. Yes the room will eat you. For example in this 2010 Screamsheet blog post, but I am very sure I have seen an older internet page that discussed the to with the stunjelly in exactly the same configuration, and after a quick search I could find Jared [von] Hindman’s 2006 article ranting about 30 years of stupid monsters, including the room of death but labeled as "Trinity of Dungeon Terror". In fact, I used his articles to build a he house filled with monsters that imitate items to try to eat you but that’s besides the point.
Has there ever been an offical Dungeons and Dragons supplement or Dragon Magazine article that employed the idea of the killer room that wants to eat you, consisting of Lurker, Trapper and Stunjelly or monsters that are virtually the same to these?1
1 – a single Greater Mimics doesn’t count. Neither does the house-sized variant unless it’s a Mimic in a Greater Mimic in a House Hunter Mimic. It must be 3 monsters.