The Irish cross used to be a symbol for
Lugh Lamfhada (long fingered). If you've ever witnessed a winter sunrise, you've seen the long streamers of pale red light. These are the fingers of Lugh reaching down to warm the earth.
After the wholesale conversion to Christianity,
stone-masons traveled throughout Ireland converting Lugh's monuments.
Lugh is often depicted (as are other Celtic deities) with certain animal features such as horns
and
cats' ears.