On the way to the Immaculates' Trial area (just as you cross into the sandstorm), you will run into a goblin trader named Kadraskaz along with his mount Ralfie.
The foul-mouthed Kadraskaz (not a friend of humankind) can be traded with (he is heading to Silverglen to setup shop near the blacksmith).
If a character with the Pet Pal talent talks to his mount, Ralfie will plead with the character to kill the mean Kadraskaz so he can finally be free of his tyrannous master.
You can also charm Kadraskaz, promising that you'll spend more than 1300 gold on his wares if he gave you the secret to killing the spider queen. This results in 4500 experience points.
If you choose to kill the goblin, be sure to do so before he reaches Silverglen, to avoid witnesses. Beware: Kadraskaz is quite tough, and has strong elemental resistances. Your best bet is to inflict slashing, piercing, and crushing damage (Rogues, Marksmen, and summoned creatures like the Armoured Undead Decapitator work well here).
Killing Kadraskaz gives 9000 XP, and Ralphie will tell you a secret about the Goblin Village...