At Suessland in Universal Studios - they had these bright red shirts that said Thing 1 and Thing 2 - I totally wanted them for my kids but they told me that they'd refuse to wear them so i didn't.

I could see one of the Uncles getting numbered shirts for Katie and Sam's brood.

It's funny how all our spawn have indestructible Uncles - Guess that's very important if you're hanging with the Winchesters