Tom had a harder time coming up with ideas, but in the end we settled on his black legging long johns, shorts, his green shirt, and a brown leather vest he'd bought at Value Village for the same friend's birthday party with a Western murder mystery theme the previous year. He also added his moccasins, 2 leather belts, a knife and a sword, and his knit beanie that I made for him with a string under his chin.
We were a little bummed, but only about a third of the people actually dressed up. We had a couple friends tell us we looked more like Robin Hood and Pocahontas than anything else! It was a fun night with good food, friends, and a few games.