Someone who is such a douchebag that they qualify for a higher level of douchebag. However, they typically aren't aware of their douche status and most don't tell them either. Guys like this are typically named Taylor or Bryce and girls like this are typically named Jessica or Stephanie.
"Hey have you met my buddy Taylor yet?"
"Yeah he's a douche."
"That's where you're wrong, he's a douche canoe."