Minions' Coffin

Powerful undead or non-good clerics that like to travel with a hidden entourage of lesser, corporeal undead favor stowing their underlings in this magic item. The minions' coffin appears to be a typical coffin for a Medium-size creature. Close examination shows that the coffin opens into an extradimensional space that allows it to store far more than would normally be possible. Up to 18 corporeal undead can be stored inside. Once the owner has filled it, she can command the coffin to produce any number of stored undead she wishes each round.
Only mindless undead, such as skeletons and zombies, generally get stored in a minions' coffin because once inside, the creature cannot release itself. An intelligent undead may choose to try to force itself out. The coffin has a hardness of 5 and 15 hp. Breaking out in this manner ruins the magic of the coffin and all its contents are spilled into the Ethereal Plane.
Caster Level: 9th; Prerequisites: Craft Wondrous Item, Leomund's Secret Chest; Market Price: 2,500 gp; Weight: 150 lbs.
Source: Web