It means the survivor had more than 2000 points when he/she died. Your zombie will also be like this if you died with more than 2000.
You'll also meet some regular "red" during the course of the game (these always have upgrades for loot). Try not to get hit by them, as they hit you for around 80% of your health on Normal (and most likely one-hit kill you on Survival)
Christmas trees are eating the pavement, The pavement is eating old ladies