Smuggler's Coffin (3.5e Equipment)
From D&D Wiki
Smuggler's Coffin: A chest built to resemble a coffin, normally made of oak or cedar, that comes in a variety of sizes. A powerful sleeping spell is infused into the wood, any sentient being placed within falls into a deep, coma-like sleep as long as the lid is closed. Once the lid is opened or the coffin is breached and light is allowed to touch the contents, the spell is broken. Occupants of a Smuggler's Coffin have no discernible bodily functions; even breathing is at the barest minimum. Smugglers and pirates use them to transport rich hostages with a minimum of fuss, but some disreputable types have begun selling the coffins to dungeon masters to use as surprise traps, since they closely resemble treasure chests.The DC for a Smuggler's Coffin is the same as a regular treasure chest, a hardness of 10 with a HP of 25 to get through the lid if it is sealed. The only way to distinguish a treasure chest from a coffin is the lack of locks on the outside; only a clasp is used to insure the lid remains down.