A Lot Shark is person with a combover that raises when the wind blows hence taking the shape or resemblence of a shark's fin
Hey Mitch That lot shark's combover stands like a shark fin when the wind blows.
A ballsack of a person who will doggedly follow a shopper from the door of a store to their vehicle where they will wait with vulpine intensity to spastically claim the newly empty parking slot. These people will constantly prowl the lot looking for "THE MAGIC SPOT".
Todd: That lot shark was stalking me and almost hit me when I pulled out!
Dan: What a BALLSACK! Stupid lot sharks!