1: Someone who turns in their friend to the cops for personal gain, personal ego, and/or what they feel is revenge.
2: Someone who pretends to be interested in things to get information for leverage.
3: Someone who looks for things in public to report to the cops.
1: "Yo, did you hear about Tnyko? He's a fuckin Pig Whistler, he fucked up and his friend called him on his shit, so the punk bitch Tnyko decided to call the cops on him."
2: "Don't talk to that Pig Whistler Tnyko, he just stores up any little thing he can blackmail you for."
3: "Tnyko the Pig Whistler's just looking for anything to report to the cops."