What was the Decorated container filled with toys and candy broken by Mexican children at Christmas?

You're likely thinking of the piñata.

A piñata is a decorated container, often made of papier-mâché, filled with candy, toys, and sometimes small gifts. It's a popular tradition in Mexico and other Latin American countries, especially during festive occasions like Christmas and birthdays.

The piñata is hung from a tree or other high point and blindfolded children take turns trying to hit it with a stick. Once the piñata breaks open, everyone rushes to collect the treats inside!