While datamining the Gamecube version of the Animal Crossing game, the miners found a file labeled "3624gMy0". When they opened up the file, they discovered a character that looked like a blue sheep with a square head. Since they were the first to find it and the sheep-like character didn't have a name, the miners gave it the name "Myo".
The dataminers then went looking in other places to find this lost media and see if anyone could recognize it. All the miners knew was that it was used as a placeholder for a furniture item even though there was coding for this file in the game for NPCs. The overall look of Myo looks pretty rough and didn't look like the rest of the Animal Crossing NPCs. No one even knows if Myo even has a gender. This baffled a lot of people and are still trying to find out what Myo is and its lore to this day.