Wallet Fly

Maybe the fly took the money...

The Wallet Fly is a species of fly indigenous to empty wallets in fiction. It hatches from an egg laid by the emptiness of its home wallet mere seconds from when it gets laid. The Wallet Fly rapidly matures from this moment forward. Once the mouth of the wallet is opened, the Wallet Fly will emerge and migrate south, never to return to its home.

It's unknown why a fly comes out of an empty wallet. Some speculate it's to emphasize on how broke the person holding the wallet is or how empty the wallet is. If you don't want to live by what the documentary above says, you can say that UnTrash Made It Happen because there's no way that a fly could just wander into a closed and empty wallet and wait to make its escape on cue when it's opened.