In Irish mythological history, Fomorians are often described as “sea pirates”.

In some tales, they’re residents of the Otherworld.  In those stories, their appearances are described as if they’re put together from the parts of other animals. For example, like a fish with legs and arms.

There are also accounts of the Formorians having one leg, one arm, and one eye.

However, since it’s hard to imagine them walking this way, there has been speculation that this actually refers to their fighting methods.

Unlike others in early Ireland, the Fomorians did not tie two warriors together to fight as a team.  Some historians suggest that the single body parts may have refered to single warriors instead of the usual team of two.

It is assumed that the Formorians lived in the sea, or under the sea, or on one of the vanishing islands near Ireland.  On charts, those islands — including Hy Brasil — were usually immediately west or north of Ireland.

We do know that the Formorians lived in Ireland repeatedly, starting at least as early as the second wave of invaders, the Partholons.

There have been several battles between the Formorians and other residents of Ireland.  For example, according to some histories,  when the Tuatha de Danann arrived in Ireland, they had to subdue the Formorians.

Today the Fomorians are almost always described as mean, ugly, nasty creatures.  We don’t know very much about them. Most literature suggests that they are very tall… and ugly.

But for all the unattractive descriptions, they seem to have provided mates for some of the Tuatha de Danann, and — like Bres, the Beautiful — their children were (and are) handsome.

Since men of the Tuatha de Danann married Fomorian women, the Fomorians might be a kind of god.

If you trace Celtic traditions, there is a strong history of the Celtic gods “of the sky” (in this case, the Tuatha de Danann) of the old land, marrying the women “gods of the land” of the new land they move to. So the Tuatha de Danann married the Fomorians.

There are later stories of the Sons of Mil (the first Celts in Ireland) marrying the women of the De Danann.

So, despite some odd descriptions, the Formorians — like the Tuatha de Danann — probably look like today’s Celts in many respects.

Until more records are discovered, we have a very weak understanding of the Formorians.