How do I get a golden Gargwa Egg?
Solution 1:
You get one the same way you do a regular Gargwa Egg; sneak up behind a Gargwa, and attack it. It will lay an egg, and it might be golden.
If you want a guaranteed chance at one, you can trade a Max Potion for one to the Veggie Elder in both the Ancestral Steppe, or the Everwood. Turns out, that's only a one-way trade. No golden eggs are available from the Veggie Elder.
Source: Kiranico