Im 102CR and i cannot pull him at all on my troller. Just bad luck? Or you cannot pull him? Seem silly if you cannot pull him as this is design to pull into the gas.
You don't pull, you lure. Just go over to the gas area. He lunges. If you have a tank, aggro does work on him. Swamp Thing is a jump around kind of guy, but always goes back to the tank.