Some Pirates from the Dead Man's Chest movie have a very Formorian feel to their appaerance, even though that is not the case.
If that's what you are looking for.
If you can't find any from the Slaine comics
There some good pictures of them from the Molach book and also on the front cover of Tara. Actualley there are good pictures of them pretty much all the way through that series.
Other wise, I don't know what you are looking for in terms of pictures.