crony
A close friend who gets unfair favors from someone powerful.
A crony is someone who gets special treatment or advantages because of their friendship with a person in power, not because they've earned it through merit or hard work. When a mayor hires his old buddy to run the city's transportation department, even though that friend knows nothing about buses or roads, that buddy is a crony.
The word carries a negative feeling. It suggests that the friendship matters more than qualifications or fairness. If a teacher always picks her favorite students for special jobs, regardless of who's most capable, those students become her cronies. When a business leader surrounds herself with cronies instead of talented people who might challenge her ideas, the company can suffer.
You'll often hear the phrase cronyism, which describes this whole system of favoring friends over fairness. Countries where government jobs go to the leader's cronies instead of qualified citizens tend to struggle with corruption and inefficiency. Organizations run by cronyism miss out on fresh ideas and talented people who could actually help.