I'm betting "woof" activated some old brain cells, so I will take a shot at the answer.

To make a cat sound like a dog, first you soak it in gasoline, then, when you light it with a match, it goes "Woof".

Follow on: To make a dog sound like a cat, first you freeze it. Then, when you put it through a bandsaw, it goes "Meeyyyyowwwww!"

If you must choose between two evils, pick the one you've never tried before.