Wikipedia
The Gytrash , a legendary black dog known in northern England, was said to haunt lonely roads awaiting travelers. Appearing in the shape of horses, mules, or dogs, the Gytrash haunt solitary ways and lead people astray but they can also be benevolent, guiding lost travelers to the right road. They are usually feared.
In some parts of Lincolnshire and Yorkshire, the Gytrash was known as the "Shagfoal" and took the form of a spectral mule or donkey with eyes that glowed like burning coals. In this form, the beast was believed to be purely malevolent.
The Gytrash's emergence as Rochester's innocuous dog Pilot has been interpreted as a subtle mockery of the mysteriousness and romanticism that surrounds his character and which clouds Jane's perception. Brontë's reference in 1847 is probably the earliest reference to the beast and forms the basis for subsequent citations.
Usage examples of "gytrash".
No Gytrash was this, -- only a traveller taking the short cut to Millcote.
Instead, all alone, sitting upright on the rug, and gazing with gravity at the blaze, I beheld a great black and white long-haired dog, just like the Gytrash of the lane.
I know this because I, Primo Kosinski, of the Black Iron Gytrash, for three full days became king of the second Sphere.