Rogue Galaxy Quarry: The Jungle Master
The closest Teleport to The Jungle Master is Path to the Leo King Ruins - Endpoint. From here just take a look at where I am on my map if you're confused about the location of the summoning circle. The Jungle Master isn't really that hard at all, but in order to actually start the fight you first need to destroy the gemstone on his head. After you destroy that gemstone you'll be able to do damage to him as normal from any direction.
That's really all there is to it. He's easy peasy.
The item needed to summon him is a Cursed Mask. They are pretty common so you'll most likely have one, even if you're fully upgrading your Revelation Flow. If you are missing the item required to summon this boss grind some battles and cross your fingers or go treasure chest hunting on a planet you've 100% the map on.
In Rogue Galaxy once you pass a certain chapter the loot table of items that can drop for you ingame is updated. What I mean is, every item has a chance of dropping off every creature after you've passed that chapter that allows that item to drop. At least this is how it works in my experience. Therefore, if you're missing any items to summon any of the quarry bosses all you need to do is grind a little until you get that item to drop for you. Good luck!