Bugsmella

Game	Yo-Kai Watch 2
Origin	Unknown
Source	Multiple Reddit posts

Nobody has managed to replicate this on purpose, though it has happened to people many times.

After the Ironworks quest in Yo-Kai Watch 2, all the Yo-Kai you befriend will simply become Badsmella. The actual Yo-Kai you were meant to get will be the one that walks up to you, but then the name will be Badsmella and the Yo-Kai you receive will be Badsmella. This can be stopped by restarting the game.