lackey
n.n. a person who follows and helps someone more powerful, often in a way that shows they are not equal. It is a slightly rude word for a servant or a loyal assistant.
n. a person who follows and serves another, typically in a subordinate or obsequious manner. Often carries a pejorative or derogatory connotation regarding the relationship of power and loyalty.
He was just a lackey for his boss.
The politician's lackey ensured that every detail of the event was perfectly organized to his master's liking.
While the protagonist was the public face of the corporation, his lackey managed the internal affairs, often acting as a buffer between the CEO and the board of directors.
Borrowed from Middle French laquais, which is probably (via Old Occitan lacai?) from Spanish lacayo, itself perhaps from Italian lacchè and Greek λακές (lakés), from Turkish ulak. Another possibility is through French, from Catalan alacay, from Arabic الْقَائِد (al-qāʔid). See French laquais.