A nat stereotype typically appears when a young teenage mexican girl of a brown skin color of some sort with bangs and eyeliner appears slightly emo, which here in the imperial valley, people would say she would look like nat first glance.
boy 1:"yo that girl kinda looks like nat"
boy 2: "thats a whole nat stereotype"
short for "Non-Natural", a person who's had cosmetic surgery.
Have you seen Sarah's mom lately? She's such a Non-Nat.