Ah Puch

In Maya mythology, Ah Puch was the God of Death and King of Mitnal, the underworld, which was the worst of all nine hells. He was depicted as a skeleton or corpse adorned with bells, sometimes the head of an owl; even today, some Mexicans and Central Americans believe that an owl's screeches signify imminent death... as the following saying, in local Spanish, indicates:

Cuando el tecolote canta... el indio muere   (When the great owl sings, the indian dies)

It is also known as Hun ahau (where the first /a/ is sometimes omitted if the words are pronounced continuously).