Similar in tone to hood rat
or street rat
the WSR is an sub-species indigenous to the greater NYC area, sometimes including Greenwich, CT. While seemingly disguised in a suit and tie this shady character is constantly plotting nefarious schemes such as parceling up bad product with enough good product to fool buyers (similar to drug dealing), insider lingo meant to confuse and distract listeners and giving themselves pay raises as everyone else suffers (stealing). They should be treated with the same contempt as other aforementioned rats.
I hate going out drinking in the Financial District. The bars are always full of stinking Wall Street Rats.