Realms of Arkania: Star Trail

This is a one-chance random encounter, so be sure to be prepared for this achievement before it happens. At your earliest convenience, purchase the item “sweets” from a merchant. General merchants usually have it, or the old lady traveling on the roads. You just need one.

Then, simply travel around until you run into the rock goat. I got it while traveling down through the woods to the right of the map. Pretty far down. When you do get the random encounter, choose the response to feed him a snack.

When your inventory appears, select the sweets, and the achievement will pop as the goat leaves.