mongoose gang, n. — Green’s Dictionary of Slang

mongoose gang n.

[1950s campaign to eradicate the mongoose in Grenada; those who claimed a bounty for killing the creatures had to produce a tail and became known as the ‘mongoose gang’]

(W.I., orig. Gren.) a group of thugs working for a politician and acting as a form of private army/secret police.

1996

Allsopp Dict. Carib. Eng. Usage.