I have seen, and heard there is a pseudo-exploit for getting the actuall Ghost of Scrapyarder, although I don't know if it was ever reported and fixed. If you wait by his de-spawn point (Black market) and hit him just as he approaches, there is the chance you will do damage right as he de-spawns, thus giving you the credit for his kill. I have actually seen it, yes. Now killing the 100 of his 'followers'...your on your own there.