I don't typically make my kids' Halloween costumes. Call me lazy, but I don't like putting that much time and energy into something that they only wear for one day. But this year my son really wanted to be an owl. And after seeing this photo:
and this photo:
I decided it was do-able. And it really wasn't too hard. There are some basic instructions and photos on the second link, just adjust the measurements for the size/age of child/person wearing the costume.