What is a barghaist?

Answer 1

A barghaist is a legendary monstrous black dog said to be capable of changing form.

Answer 2

A barghest is a mythical monstrous black dog in northern English folklore, often said to be an omen of death. It is known for its glowing red eyes and ability to shape-shift into other forms. Tales of barghests are often linked to mysterious happenings and ghostly sightings.