The correct way to obtain the Groupie Achievement.
How to Obtain Groupie Achievement
For this achievement we want that Damu, the Camel-boy come to our camp. For this to happen, we need impress him first. And to do that we need to show him our Bravery.
Damu can be found at Bezer, the village of the Dustfolk. Since we want get there with the Brave's trait, I recommend starting your journey in another village.
The most indicated is the High Tribe, since we can encounter Calfmother Lahara in the first map, chose "Hurry" and obtain half of the Brave's trait. At the village, we just need to look at the Pale Dancer's statue to adquire the other half of the trait we need.
Nowing that, before entering the High Tribe's village, search in the "World's Map" for the Dustfolk's village: Bezer. If you found it, great, you may continue. If not, start again until you met this prerequisites.
With the Brave's trait, at Bezer you must talk to Damu. For now, he will be impressed by your bravery. After that, at your next camp, Damu will visit and ask you how he can be as brave as you.
It's important that you "Greet" him at your camp rather than "Attack". The latter will scare him and he will drop some opals. The first will give you the achievement.
PS: It's also important that you don't cook at this camp, as cooking is a way to avoid in-game encounters and gain / change traits.