Yesterday while exploring the Jungle in a new 1.3 World, I encountered something very interesting. Suddenly a gold-ish swirl appeared directly on top of me, and started to drop goldpieces. It stayed for a very short time, maybe five seconds, and then disappeared after dropping about 10 gold. I was busy evading hornets and slimes, and I died soon thereafter anyway, so i do not recall what triggered it.
Is this random? Can I intentionally trigger this? I did not see it mentioned in the wiki yet.