Found these this weekend as well. I don't know if they're greyhounds or zombie dogs or what! Crazy looking things I did not polish once he can actually see what they look like. And of course I can't figure out the maker either.
Those are great...they go well with the penannular broach you posted the other day (in that it's a Celtic design). From the Book of Kells, it's called a "triskell".
I actually have this design on my truck window.