Barrel of Monkeys

The Barrel of Monkeys is a special agent that is actually five towers. The towers included are random, with random upgrades already given. However, more powerful or expensive towers and upgrades have a lower probability of being included. It costs $600 Monkey Money, and you can't see which towers you've gotten until you drop the Barrel into the game area. Once placed, the towers from the Barrel can be upgraded normally, but cannot be sold.