Held up remarkably well!!!
My 20 month old fit perfectly into the 12-18 month size (but he's on the small size for his age). I think it runs a little big, so would recommend sizing down if you're on the fence. I was SUPER impressed by how well the feet held up on this costume. My son walked probably about 1-2 miles on the sidewalk in this costume and the feet don't even look worn. Not even the red foot print looks worn! I figured that after all the walking, there would be holes or tears in the fabric but it still looks great! He even wore it on a damp grass field for a bit and it didn't soak through to his socks underneath. He was comfortable and happy in the costume all night. Occasionally, the hat would fall a little forward on his face. But even so, he wore it for most of the night. Really happy with this costume!