Nicky Chang is a man who appeared in Pu'olo (episode) and who works in the black market and who sold a man named Richard Detweiller 100 chips for passports from Chang himself.
Hawaii Five-0 later attempted to take him down, only for the members to back off when Chang attacked them with a flamethrower.
Luckily, though, Lieutenant Commander Steve McGarrett managed to get the drop on Chang by crashing into him and stopping Chang from using the flamethrower any further.