Chris Hastings is the man behind the internet's premier medical/ninjitsu soap opera, Dr McNinja. And you know what? He's also the man behind this reasonably badass Mario Bros. shirt.
It's called Warrior Plumbers, and...well...you see what it does. It's $19.75 plus shipping, but by the time you read this, they'll probably all be gone. Sorry!
Warrior Plumbers [TopatoCo, via Boing Boing]