henchman
US /ˈhentʃ.mən/
UK /ˈhentʃ.mən/

1.
a trusted follower, supporter, or assistant, especially one who performs unpleasant, illegal, or violent tasks for a powerful person
:
•
The crime boss sent his henchman to collect the money.
•
The dictator relied on his loyal henchmen to enforce his rule.