Bounty Hunter. Starts in Chapter 1, this is where you first cross paths. Goes overboard in Chapter 2. All out awesome brawl in Chapter 3. Their leader messed with the wrong Hunter, get your print screen ready, some really awesome shots in that fight.
That guy is not the leader of the Green Jedi. He is one of the big Masters of the higher overall Jedi Order, and chief adviser to the Supreme Chancellor of the Republic.