Miner Forty-Niner

For the most part, he remained expressionless throughout chasing the gang. At times he grunted, as well as, letting out moans to scare people. He seemed genuinely shocked when he was fooled into thinking he was in the path of an incoming train, the surprise in his face, lifting his hat and revealing his eyes.

He was, according to Hank (who was using the disguise to find oil in the mines), obsessed with trying to find the last vein of gold in the mines since 1849.

He attempted to grab Scooby-Doo and the gang at some points, but that's the extreme of his actions mostly.