Alternative for huckster
Unscrupulous
un·scru·pu·lous
ˌənˈskro͞opyələs
adjective
having or showing no moral principles; not honest or fair.
Maybe unscrupulous shark (credits to JEL and IconDaemon for "unscrupulous").
Example: Morgan, who seems to monopolize every major and minor trade in the country, is the stereotypical unscrupulous shark, who always finds justification for his actions.