Many versions of this one can be found bouncing around the Internet.

A frog walks in to a bank one day and asks the teller for a loan. The teller goes to the back and asks her boss what to do. The boss says, “Tell the frog to go see Patty Black at the loan desk.” So she does, and the frog asks Patty for a loan. Patty asks if the frog has any colateral. The frog says, “I only have this plastic elephant.”

So Patty goes to ask her boss what to do. She says, “There is a frog out here with a plastic elephant asking for a loan. What ever should I do?”

To which her boss responds, “it’s a nick-nack, Patty Black, give the frog a loan.”

Ken McDonald reminded us of another version.

It seems that the frog first introduces himself as Kermit Jagger, and his father is an enormously wealthy rock star, and he hints that repaying the money is not a problem. The punchline then becomes, “It’s a knick-knack, Patty Black, give the frog a loan. His old man’s a Rolling Stone.”