The Miner is a man who works at the Strip Mine. He asked the Kridder Ridder Extermination Company help him kill the Metal Bugs and retrieve his beloved Eco Crystals. Apparently, he makes a good profit and is quite pleased with his work because he mocks the ordinary citizens of Haven City.
The miner comes across as lazy, as he orders Daxter to retrieve the Eco Crystals.
The miner holds an axe for mining reasons, but he presumably has more equipment.