Police Cookie (also called Cop Cookie) is a non-playable Cookie in Cookie Run. Police Cookie appears in a pop-up whenever the game detects cheating or hacking. They will "warn" that further unfair play will have consequences (up to permanent ban from playing the game). Its first known public appearance was found inside one of the Clean-up Campaign newsletters.
Additionally, Police Cookie appears in name only on Kiwi Biker Cookie's Motorcycle License. Most likely their approval is needed to make a license official judging from the stamp next their name.