A Piñata is a must nowdays in any birthday occasion may it be for babies, kids or older people.  It is usually and traditinally made of paper mache modeled to resemble objects or certain characters.  The design is limitless, it can be almost anything you wish to be.  Many different versions of piñatas are available in most party supply store and mexican groceries.  Some are made of paper mache and some were innovated materials like cardboards, and other containers.

A piñata is filled with goodies:  candies, toys and other things that can be good for loot bag stuffers.  To break a piñata open one must whack it or hit it with a stick until it breaks.  Another way is to have it done with a trap door and opening it with pull strings and colorful cords.  This kind is ideal for toddlers who don't have the coordination and power yet to hit and break a piñata. 

Stuffing the piñata is the fun part.  You can get all the goodies you like, the more colorful the better.  Kids love to see the goodies fall like a confetti.  If you have candies left during the Halloween trick or treating then you make good use of those or better yet buy candy fundraisers, this way you can also help even a bit with your purchase.  Marsmallows individually wrapped will make a very nice stuffer, it's light and ids love it too.  Whatever you want to put in there totally depends on you, no specific rules and no certain restrictions.