Hi Maria!
Welcome to the Collectors Board!
The majority of the fantasy pins you see are made by individuals not associated with Disney. Most of the time it would be a collector or fan that wants their own pin to give to friends or trade for other fantasy pins (or even some authentic Disney pins for some of the cuter ones!)
There are a number of manufacturers of pins that will produce a pin to your specific artwork. Or if you are not artistic but have an idea of what you want it to look like, they will create it for you. You do have to be careful not to break any Disney copyright laws!
It's not a cheap venture - most pins will cost you over $2 each to make and most manufacturers have a minimum of how many you have to buy. I'm not positive but I think most of them want you to order at least 100 for it to be worth their time and profitable for them.
Some of the fantasy pins can even be nicer than official Disney pins and have some interesting combinations of characters or companies on them, Like Marilyn Monroe and Mickey or Uncle Scrooge carrying a can of Coke. Unfortunately, a lot of the fantasy pins are somewhat cheaply made and aren't as nice looking in person.
Just be careful what you are paying for if you get it on eBay - and maybe save collecting Fantasy pins for when you are at WDW since you will be able to get a better idea how they are made.
