A person who should learn to stop being a rat
OMG you are being such a little rat
The animal that's truly in the top of the food chain. The one and only species. The messiahs. One day the rats will consume us all, and we shall be thankful. All hail the rats.
JOIN THE RAT CULT. BECOME ONE OF THE RATS.
A "rat" is a traitor, a conceiver, planner or physical participator
He doesn't sell secrets for power or cash, he betrays the trust of his team or his family hoping to save his own cowardly ass
The difference is, at least a snitch is human, but a rat is a fuckin' rat, period
He snitched on us, that fucking rat.