Wondrous Item, very rare
This bag looks exactly like a bag of holding except it has a button on it that looks like an eye. upon opening the bag a Beholder type creature will escape, roll on the table if your players are foolish enough.
D8
1: Average Beholder
2: Death Kiss
3: Gazer
4: Gauth
5: Spectator
6: Mind Witness (under the opener's command)
7: Zombie Beholder
8: Death Tyrant with (Highest Player's Level)+D4 Zombies
Notes: Control, Utility, Combat, Container