You use it to talk about girls who are ugly sluts.
It originated on the island of kauai at kula school.
D Mar is such a trog, she fucks a new guy every week.
In the film 'Bang Bang You're Dead', the Trogs were planning to get retaliation against the Jocks by having a shootout in the school cafeteria.
Trevor - "Trogs. Guns."
Girl - "Did you hear that the Trogs started hanging out with the 'Mad Bomber'?"