Warleader Garn Side Quest - Unknown World (Kotor 1)
Start Location: North Beach
Cut Off Point: Siding with 'The Elders' or when you leave Unknown World
Reward: 1000xp & multiple items
In order to complete this Side Quest you'll need to be friendly to the Rakata on the Unknown World. To become friendly to them accept their invitation to speak with The One and agree to help him out. Even if you turn against The One later on so long as you agree to help him you'll be friendly to all Rakata in the area.
You'll find Warleader Garn on the North Beach standing in the pack of Rakata roaming around in the central part of the area. Speak with him to start this quest, he asks you to collect the head of the Mandalorian Captain in the Unknown World - Temple Exterior area.
When you approach the area just south of the Temple's entrance you'll trigger the fight with the group of Mandalorians. They are quite difficult since they constantly stun you but they're weak to force powers so keep that in mind when fighting them. Loot the leader's corpse when you're done and I recommend you immediately return the head to Warleader Garn.
During the story quests on this planet you'll have to choose a side and depending on your choice you may turn the Rakata against you. For this reason it's best to turn in the quest right now while they're all still friendly towards you. Your reward will be a footlocker full of really good items (including the best shield in the game) and 1000xp.