Worse than a "Rat Bastard". This individual will be cordial and charming to your face, then instigate despicable acts against you behind your back. A lying, coniving piece of worthless humanity. The essence of immense evil.
Teacher #1: That school board president has been telling everyone that he runs this school, not the superintendent.
Teacher #2: Mr. Sellers told me the same thing, but kisses up to the superintendent in public.
Teacher #1: We need to get out of Pawhuska, he is a rat basturd!