David Kosse

Indeed, he is not where stated on the map as of 17/10/2012. Both the speech bubble and the blue overlay are incorrect.....

He can be found at coordinates 62.98,54.57

NPC part of the Battle Pet Tamer: Eastern Kingdoms quest linked below:

Battle Pet Tamers: Eastern Kingdoms

He will encounter you with 3 pets:

Subject 142: This pet is a Critter, I recommend using a strong and fast Beast. This pet has Dodge which is an trigger ability gaining 100% dodge for 2 rounds, he will keep attacking you (has 724HP in combat)

Corpsefeeder: This pet is a Beast, using a mechanical creature is my suggestion since you might need a back-up plan for Plop (last pet of the encounter). Corpsefeeder is very tricky since it has Consume which is pretty much a drain life and Sticky Goo which will hold you from switching your pets ability for 4 rounds (has 880HP once in combat)

Plop: This pet is Magic so I also recommend using a mechanical creature with CC abilities such as the Personal World Destroyer (has 794HP once in combat)

Good fight and add whatever is necessary to update this comment =D

This is frustratingly odd, On my way to go engage Mr. Kosse and let my trifecta of Pets lay a whoopin' on his 3 pets, and the white comment bubble shows on my mini map yet when I land his Image/NPC is nowhere to be found.
Has this by chance happened to anyone else?