Eccentric Exterminator

In Real Life, practicioners of pest control are usually like any professional who practices a job, but such is not the case in fiction land. Perhaps it is the sinister nature of the job, or the fact that it's not a job conductive to making friendships, but there's something in the image of the exterminator that has turned it from quirky to living Cthulhu of the pests.

See also Egomaniac Hunter.

Examples:

Ceasar from Mousehunt, played by Christopher Walken, from all people.
Dale Gribble from King of the Hill.
The protagonist from Naked Lunch, making this Truth in Television in the case of William S Burroughs.
While not exactly an example, the first Men in Black movie gives us Ed, which is a pretty normal fella (or as normal as someone played by Vincent D'Onofrio can be...) until a bug from outer space uses his body as disguise and steals an exterminator's van, giving us quite a bit this vibe.
The Exterminators is a Vertigo comic book with an entire cast of eccentric exterminators.
The men who get stuck killing rats in Stephen King's Night Crew.
John Goodman's character Delbert Mc Clintock in Arachnophobia. He acts like he's the greatest thing ever, even though he really doesn't help a whole lot.
In the Dexter season five episode "Hello, Bandit" the titular Dexter tracks down an exterminator who is also a serial killer.
One appears in Over the Hedge.
Little Richard plays one in a episode of Martin
Real Life/Reality TV example: A&E's Billy The Exterminator. Besides dressing in goth clothing as a substitute for more practical protection, he is perpetually excited about pretty much everything.
Any rat catcher in the Discworld novels so far. And it seems the job is The Verse equivalent to a Red Shirt by the way, unless you're a gnome of course.
- Sometimes it's even better than Red Shirt. At least one of these guys upon dying was greeted with "Squeak!" and... reincarnated. No prize for guessing into what exactly.
The perst control guy from the Itsy Bitsy Spider animated series.
In The X Files episode "War of the Coprophages", a cockroach exterminator opens the episode with a heartfelt ode to roaches before finishing it with "But to them, we humans are gods and should act accordingly" and stomping a particularly unlucky specimen on the floor. It doesn't end well for him.