So far I've only found one golden egg in GHV, and it is in the forest that always looks sorta smoky where the challenging race is. There's a quest in that area to gather leaves that are floating in the air and there's also a hidden quest there for the smugglers. I found three egg hunts while I was there, though. One given by Jasper at the pumpkin farm, one by the mayor of Cape West Fishing Village, and one from the race giver at the stables.
Veronika Starstorm's musings and helpful pointers on the world of Star Stable Online