The Baku is a dream-eating spirit from Chinese and Japanese myth.
While it is usually portrayed as a tapir in modern depictions, the baku was originally a chimerical creature. The earliest known description of it describes it as a shy creature with an elephant's trunk, rhinoceros eyes, an ox tail, a bear's body and tiger paws. In this form, it has yellow and black colouration. However, it has also been shown as a tiger with horns and an elephant's head, and, more rarely, a nine-tailed goatlike animal with four ears and eyes on its back. Legend has it that it was created with the spare parts the gods had after creating all of the animals.
Baku are generally benevolent creatures that will eat a person's nightmares - or the spirit causing them - if invoked. Their pelts are a talisman against illness and evil, as does putting an image of the baku over one's bed. Evil spirits will flee from these creatures, so they leave a trail of health and good luck behind them.
However, occasionally it may be unsatisfied with just a nightmare and may devour their hopes and dreams as well, leaving the victim an empty husk. Baku have even been known to plague houses, devouring the dreams of anyone inside to the point of insomnia. Despite this risk, it is generally accepted as a helpful spirit.
The first dream of the new year in Japanese legend is said to determine how the year will go. As a result, people will often invoke the baku in hopes that it will devour their nightmares and leave them with a good dream and, subsequently, good luck in the new year.