Fuglymon was first discovered in the early 1500s. Back then, they were classified as witchcraft. Leonardo DaVinci, a polymath of the Renaissance, was among the first humans that came into contact with these entities. Leo studied some of them and based a lot of his work on these creatures.
It wasn't until 1991, when Stuart Haber and W. Scott Stornetta discovered the access to the Blockchain. These two researchers wanted to implement timestamps that could not be tampered with. Two decades later, Bitcoin (a rare Fuglymon) was discovered and contained on the blockchain itself for security purposes.
It is still a well hidden fact that The blockchain not only stores data and transfers, but also opens virtual gateways to other dimensions. These "doors" remain open for a very short period of time, but as long as it remains open, entities from other universes can easily go through.