I kinda need help with this one.
In the Act 2 sometimes you get a bounty to kill Snitchley - a purple goblin. I had it once, killed him ASAP (like I'd do with a normal gob) and then it hit me: he's a target of a bounty, so he SHOULDN'T be able to warp away. Maybe it's possible to clear the area around him, attacki him once and let him run all over the place droping gold/lootz for hours...?
If someone can find him before I do again - please post your findings!