This is how the Golden Fleece looks like in 0 A.D.:
The problem is that only the fleece (wool) was gold, the animal itself was not. It was sacrificed to Zeus after flying Phrixos from Greece to Colchis (coastal Georgia); his twin-sister Helle fell off halfway, giving her name to the Hellespont. Here is a 3rd C BC coin depicting Phrixos on the flying ram:
Now I guess it was added to the game as a fun easter egg, however, it is important to get things right, even if it's a mythological animal.
This patch removes this incorrect actor and template, and replaces it with the ordinary metal treasure in the map files.