The device is a deterrent to theft. Triggered by proximity or movement, the blade barrel unfolds, and up to 10 articulated arms slide out of hidden panels. Each of these arms terminates in a scalpel-sharp dagger blade capable of slicing bone. These arms hover like serpents waiting for any sign of movement. Clockwork sensors and phlogiston-directed vanes detect motion near the blade barrel, and anything larger than a rat is subject to a lethal series of attacks. Blade barrels appear to be normal barrels of goods or warehouse crates. Cruel or malicious goblins often tip the dagger arms with venom to mark anyone that the blade barrels daggers slash. The blade barrel lashes out at anything that stumbles within its 10-foot reach.