Dia de los muertos

In Christian countries November 2nd is the day when people remember their dead.

In particular in Latin America this celebration has nested itself onto a precolumbian festivity and it still keeps great importance in everyday life too.

Every people in fact, in every corner of the world, has a festivity dedicated to the dead which was always held at the end of the harvesting season, when earth rests and seems to die after the abundance of Summer.

The major difference between ancient rituals and the christian Day of the Dead festivity resides in how they are celebrated: anciently, and still today especially in Mexico, the day dedicated to the dead was a day of joy, when people showed their dear dead that they're still loved and that we want to share with them our happiness, leaving offers on their graves: food, their favorite beverages, small gifts.
The day of the dead becomes the day when we celebrate life and consequently also the symbols representing this festivity often join life and death, a famous example being skulls and flowers, often designed in a colorful and playful style.

Halloween itself has its own roots in a pre-existent Celtic festival and marks the time when spirits freely roam on earth, while she prepares herself for the long Winter sleep.
The modern party gets thus populated with goblins, skeletons, ghosts, monsters of all kinds and, of course, bats:

One of the most renown symbols is the calaca, also named Catrina or Calavera Garbancera, which got famous also thanks to Tim burton's movies: it's a skeleton dressed up in female clothes, often as a bride, and it is also an all-time favourite Halloween costume.