Chet

Chet is one of the Leviathans hunting for Sam and Dean.

Background
He had token over a man working at a place that tracks credit cards. He was on the phone when Sam's credit card alias popped up. Looking at the location it was used, Chet heads to the location. When he gets there, he ties up the shop owner and reviews the security feed, and sees that Sam Winchester was there. He calls the higher ups.