It is said that he can change his size from a very small creature to a very tall man. He is known to rescue humans who have become trapped by fairy magic, or to play games in human homes at night. Sometimes the Far Darrig asks a human to allow him to warm himself at the human's fireplace. If the Far Darrig is refused, he might play tricks on the unkind human. Ireland has many haunted castles, lakes, bridges and roads.
Irish ghosts can appear in human shape or as almost any kind of animal.
The Dullahan is a headless coachman who drives a carriage pulled by headless horses. Some Irish ghosts go about their own unfinished business, while others warn humans of danger. The Puca usually sneaks up behind an unsuspecting person, flips him onto his black back, and takes the person on a wild ride. Often the Puca takes the person to a place where good things happen to him, if the person has shown respect and kindness to the Puca. A Merrow is a water creature who is half human and half fish.