handlanger
An unskilled assistant to an artisan.
[…] building himself brick by brick, with his wife as his only handlanger.
An aide, an assistant.
figuratively
[E]very political leader has a handlanger. Like a toddler with a security blanket, the political handlanger is a necessary sop and sponge for all the tension that goes with the job. And there is nothing either disreputable or degrading about the role. Politics can be spiteful and demanding; the handlanger is the trusted confidant, the one person whom the leader can sound out, seek counsel from and trust.
Where it comes from
Borrowed from Afrikaans handlanger (“assistant, helper”), from Dutch handlanger (“accomplice, henchman; assistant, helper”), analyzable as hand (“hand”) + langen (“to hand over or pass to”) + -er (“-er”, agent suffix) (in the sense of someone who puts things into another person's hands), from German Handlanger (“handyman; henchman”), from Hand (“hand”) + langen (“to hand over, to give; to reach for something”) + -er (“-er”, agent suffix).
Adapted from the Wiktionary entry handlanger (CC BY-SA 4.0).