Will a banker joke do?

A frog walks into a bank and sits down at the desk of loan officer, Patty Black.  The frog, in need of a loan, places a sea shell upon the desk.  "What's that for?" asks the loan officer.  "It's collateral," replies the frog.  The loan officer explains to the frog that a sea shell is not sufficient collateral for the loan.  So, the frog says, "Mick Jagger is my dad" and demands to see the bank's manager.  The bank manager appears, listens to the story, looks at the sea shell, looks at the frog, looks at the loan officer, and says:  "It's a knick-knack, Patty Black.  Give the frog a loan.  His old man's a Rolling Stone!"

Get it?