Derek Dietl is the secondary antagonist and the former fiancé of Susan Murphy in Monsters vs. Aliens.
He is a weatherman who engaged to Susan but always saw his job more important than her by saying on their wedding day that they would go to Fresno instead of Paris for the honeymoon.
After Susan becomes a giant, Derek breaks off their engagment as he doesn't not wish to get married to someone who would overshadow his career.
At the end of the film, Derek (for his job) tries to interview Susan. But she as revenge throws him up in the air and then let's B.O.B. swallow him and spit him back out.