Definitely want to make some capes from adult tee shirts. If cut the neck and add velcro for safety though. No-Sew Superhero Cape from a t-shirt. The post has a tutorial for toilet roll superhero cuffs too.
T-Shirt No-Sew Superhero Cape - Cutesy Crafts
How to make Superhero masks, cuffs and t-shirts (including free templates) :-) // Ranch Monday - Zero to Hero
Transform yourself into a superhero for Halloween, starting with your feet
12 Super Hero Themed Craft Ideas - Perfect for Hero Central VBS - Visit to grab amazing Super Hero Dry-Fit Shirts, now on sale!
No sew superhero cape from t-shirt
Brigitte K's Birthday / Superhero - Photo Gallery at Catch My Party
How to Make a DIY Cape Easily. An easy gift to make for a kid! we could just sow a hood on the back and arm holes in the side.