Day of the dead is the Catholic, and generally Mexican(although its celebrated in most north and south american places) holiday celebrating
All Souls Day, aka Halloween, aka the ancient Samhain.
It's celebrated with skulls, skeletons, candy, camping out in cemeteries, and amateur seances. It's every goth and emo kid's dream day. Also called
Dia de los Muertos.
It is one kick ass holiday.