Cartoons aren't always funny.

That's the lesson Sam and Dean will learn this Wednesday on Supernatural, when they investigate the case of a man's heart literally bursting through his chest on "Hunteri Heroici" and soon find a small town where many deaths resemble those we typically witness on Saturday mornings.

The brothers will also be assisted on the case by Castiel, who is anxious to become a hunter.

Watch him in action below and look forward to this brand new Supernatural Season 8 episode:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.