While Mitchell is setting up a Wizard Of Oz-themed birthday party for Cam, the waiters who are to play the flying monkeys show up. They announce themselves like this:

First Waiter: "Hey."

Second Waiter: "Hey."

First Waiter: "We're the monkeys."

Get it? And to think this episode, which must have been made weeks before, was shown on the day Davy Jones died. :(