He sets them down on the bar and says to the bartender,
"I bet you $1000 that my frog here can sing any song you can think of."
"Ok," says the bartender. "How about 'Blue Moon'?"
The man whispers something to the frog, and the frog starts singing blue moon.
"That's amazing," says the bartender as he slaps down $1000.
"I'll bet ya another $1000 that my iguana here can do that to."
"Ok, I can believe a frog, but not an iguana. You're on. Have him sing the Star Spangled Banner."
The man whispers something to the iguana and it sings the Star Spangled Banner.
As the bartender hands over another $1000, a businessman comes up and says,
"I just saw that and I was amazed. I want to buy your iguana for $100,000."
The bartender said, "What are you nuts?! You could have made millions with that iguana!"
The man said "Oh, the iguana can't sing. The frog's a ventriloquist."