New Caterpillar

Haven't seen this one here before. It may not be rare. It's just that I haven't come across one before. 

I've worked to develop the habit of noticing creeper/crawlies. Since I don't spray my gardens with pesticides, I need to be more observant. Non-chemical control of pests works best when started immediately, not days or weeks after the new pests arrive. 

Is this one a pest? I don't know yet. But I'll let him be for now.