#bulcomon

The common scenario is that when a Digimon is made outside of Japan, they have little chance of becoming an official Digimon (see Snowballmon and Snowmanmon), so some people though it wouldn't become an official Digimon, even though Digimon Encounters is produced by Bandai China.

However, a discovery was made!

Originally, when the Digimon Pendulum Ver. 20th was tab cheated, all 15 of the Password Digimon were discovered for it. What was originally thought to be Filmon turned out to be Bulcomon! That coupled with the fact that Sistermon Ciel was discovered as well (alongside NEO and Erismon) means it is an official Digimon.

So, we knew about Bulcomon's existence...but it was assumed to be another Digimon!