Your question isn't clear. Are you referring to counter-fiet coins? These are coins made illegally for profit. They are considered fake as they are not minted officially.
because they don't want you to now it is fake
A counterfeit coin is often referred to as a fake or a forgery.
The magicians should be called sorcerians and the world called voltarnia.
What do you refer to as the "the original AUS coin" and why do you think you have a fake?
Cunning manual dexterity used especially by card sharps, jugglers and magicians, also called Prestidigitation
They are called Magicians.
That's called a wand.
A magician's helper or assistant is sometimes called a famulus.
That could be a very rare coin. Take it to a coin dealer to have it appraised. Call them first and ask. Do not tell anyone you have it. Virtually EVERY double-headed coin that turns up in circulation is a fake. They're called magician's coins and sell for a few bucks at novelty shops. If your coin makes a hollow or dull sound when clinked on a table it's a magician's coin.
Look for a seam along the rim edge of the coin which would mean is a casting and fake. Check the weight. An authentic coin should weigh 268.5 to 269.5 grams. Much lighter or heavier means fake.
If you doubt the authenticity of any coin, take it to a coin dealer.
Then it's a fake. It's called a magician's coin. Try using this site's Search feature - enter the word DOUBLE and you'll find hundreds of similar questions.