Scourge of Zem'lan

There are three kinds of interactable objects at the Port of Zem'lan. Each of them grants you a 10 mins buff.

• 
  
• Pirate Hat grants [spell=268462]
• 
  
• Zem’lan Blackeye Brew grants [spell=268468]
• 
  
• Treasure Map grants [spell=268464]
• 
  

Once you have all these three buffs at the same time, Ol' Bonebite will pop up and stay with you as long as these buffs exist.
Each object respawn in around 15 minutes. Currently, the object does not glow or show outline so you need to find them with your bare eye.

Here are some of the locations:

TomTom

/way Vol'dun 36.80 79.90 Brew
/way Vol'dun 37.08 79.98 Brew
/way Vol'dun 37.13 78.11 (in a chamber)
/way Vol'dun 33.77 78.76 Hat
/way Vol'dun 34.13 78.35 Hat
/way Vol'dun 34.73 80.14 Hat
/way Vol'dun 35.80 76.65 Treasure Map (in a chamber)
/way Vol'dun 34.83 76.75 Treasure Map (on the wall)

1. 
   
2. Collect 3 buffs from items in the area. (Need to have all 3 at the same time)
   
   • 
     
   • [object=287495] buff [spell=268462] in center / south-west part
   • 
     
   • [object=287498] buff [spell=268468] in south-east part
   • 
     
   • [object=287496] buff [spell=268464] in north part
   • 
     
   
   

   Items image and location map: https://imgur.com/a/3HewhHT

   
   Items of the same type have shared instant respawn cd
   At least one item of each type is always up
   You can loose buffs if you leave the area or any 10 minutes buff timer expires or you die
   
3. 
   
4. When you have all 3 buffs Ol' Bonebite spawns and follows you like a pet
   Kill 20 pirates in the area while accompanied by him
   Don't forget about [spell=254366] debuff +10% damage taken
5. 
   

Achievement demo: https://www.youtube.com/watch?v=soERLnS_6bg

TomTom coordinates of all locations:

Spoiler

You probably don't need that many, but still

Show Map
/way Vol'dun 34.55 80.86 Hat (On a box)
/way Vol'dun 34.75 80.12 Hat (On the ground near [npc=128297])
/way Vol'dun 35.02 79.37 Hat (On the ground)
/way Vol'dun 34.42 81.38 Hat (On top of 3 boxs)
/way Vol'dun 33.86 77.91 Hat (On a box)
/way Vol'dun 35.21 79.93 Hat (On a rock)

Show Map
/way Vol'dun 34.80 76.86 Map (Inside on the wall)
/way Vol'dun 34.69 77.20 Map (Inside on the wall 2)
/way Vol'dun 34.85 76.72 Map (Outside on the wall)
/way Vol'dun 34.76 76.96 Map (Inside and outside on the walls)
/way Vol'dun 35.03 76.04 Map (On a pillar)
/way Vol'dun 35.23 76.61 Map (On the ground)
/way Vol'dun 35.79 76.66 Map (On the ground Inside)

Show Map
/way Vol'dun 37.08 80.01 Brew (On the ground inside)
/way Vol'dun 36.99 80.04 Brew (On the ground inside)
/way Vol'dun 36.80 79.92 Brew (Outside the house)
/way Vol'dun 36.24 78.41 Brew (On the ground near boxes)
/way Vol'dun 36.39 78.61 Brew (Buried in sand)
/way Vol'dun 37.12 78.12 Brew (Inside, behind the boxes)

Achievement was discoverd and well explained by Peterodox.
I'm just putting some additional info, screenshots, extra tomtom coordinates and video.

To earn the achievement you need to travel to Port of Zem'lan area, Vol'dun Zone.
There are three items you have to find and use to summon Ol' Bonebite:

• 
  
• [object=287495] - can be found within some radius from 35.2 79.8 spot. Looks like, well, pirate hat.
• 
  
• [object=287498] - search for it in buildings east of pirate hat spot.
• 
  
• [object=287496] - search for map around 34.9 76.6 spot. On walls or inside buildings.
• 
  

TomTom:
/way Vol'dun 35.2 79.8 Area to search for Pirate Hat
/way Vol'dun 37.1 78.1 Area to search for Zem'lan Blackeye Brew
/way Vol'dun 34.9 76.6 Area to search for Treasure Map

Best way to earn this - locate all of the items first, then collect them and slay pirates until you got your Scourge of Zem'lan.
Dont die or leave the area, otherwise Ol' Bonebite despawns.

Scourge of Zem'lan - www.youtube.com/watch?v=AAh_DwkTqNk