It'd be a bigger pinterest post, but I've gotta work on making my other image smaller... bummer. Anyway... Saw on pinterest a little snip snip here and another snip snip there on an old t-shirt to make a little boy (or girl, for that matter) one nifty, spifty cape.
SO - when I discovered a hole in one of my t-shirts I thought "tada", and here is our Superhero in all of his glory, and it took me all of 2 minutes with a pair of scissors.
Note - you can run so fast with these capes that the neck becomes a litttttle stretched out ;)